有平滑度的线怎么让前面一部分展示实线，一部分展示虚线echarts 柱状配置项内容和展示

2018-2019这段距离需要用虚线展示

      
        var xData = function() {
            var data = [];
            for (var i = 2011; i < 2020; i++) {
                data.push(i);
            }
            return data;
        }();

        var data = [13.7, 13.4, 13.5, 16.1,13.4, 13.5, 16.1, 17.4,{
            value :15.2,
            //自定义标签样式，仅对该数据项有效
            label: {},
            //自定义特殊 itemStyle，仅对该数据项有效
            itemStyle:{
                color:'#d9761b',
                borderColor: '#fb8c07',
                borderWidth: 1,
                borderType: 'dotted',
            }
        },];
        var dataline = [13.7, 13.4, 13.5, 16.1,13.4, 13.5, 16.1, 17.4,'null','null'];
        // var dataline = [13.7, 13.4, 13.5, 16.1,13.4, 13.5, 16.1,17.4,17.4,16.1,'null'];
        var datalinedotted = [13.7, 13.4, 13.5, 16.1,13.4, 13.5, 16.1, 17.4,16.1];
       option = {
             backgroundColor: "#0c2641",
            tooltip: {
                trigger: 'axis'
            },
            legend: {
                data:['产值增速','增加值增速'],
                textStyle:{
                    color:'#eeeced',
                    fontSize:14,
                },
                top:'5%',
                icon: "rect",
                itemHeight:8,
                itemWidth:8,
                itemGap:30,
            },
            grid: {
                left: '3%',
                right: '8%',
                bottom: '3%',
                containLabel: true
            },
            xAxis: [{
                type: 'category',
                axisTick: {
                    show: false
                },
                axisLine: {
                    show: true,
                    lineStyle: {
                        color: '#363e83',
                    }
                },
                axisLabel: {
                    inside: false,
                    textStyle: {
                        color: '#bac0c0',
                        fontWeight: 'normal',
                        fontSize: '12',
                    },
                    // formatter:function(val){
                    //     return val.split("").join("\n")
                    // },
                },
                data: xData,
            }, {
                type: 'category',
                // name:'产值增速%',
                axisLine: {
                    show: false
                },
                axisTick: {
                    show: false
                },
                axisLabel: {
                    show: false
                },
                splitArea: {
                    show: false
                },
                splitLine: {
                    show: false
                },
                data: xData,
            }],
            yAxis: [{
                type: 'value',
                name:'产业增速(%)',
                scale: true,
                nameTextStyle: {
                    color: '#e3e3e4',
                    fontWeight: 'normal',
                    fontSize: '12',
                },
                axisTick: {
                    show: false
                },
                axisLine: {
                    show: false,
                    lineStyle: {
                        color: '#32346c',
                    }
                },
                splitLine: {
                    show: false,
                    lineStyle: {
                        color: '#32346c ',
                    }
                },
                min:0,
                axisLabel: {
                    textStyle: {
                        color: '#e3e3e4',
                        fontWeight: 'normal',
                        fontSize: '12',
                    }
                }
            },
                {
                    type: 'value',
                    name:'增加值增速(%)',
                    scale: true,
                    nameTextStyle: {
                        color: '#e3e3e4',
                        fontWeight: 'normal',
                        fontSize: '12',
                    },
                    axisTick: {
                        show: false
                    },
                    axisLine: {
                        show: false,
                        lineStyle: {
                            color: '#32346c',
                        }
                    },
                    splitLine: {
                        show: false,
                        lineStyle: {
                            color: '#32346c ',
                        }
                    },
                    axisLabel: {
                        textStyle: {
                            color: '#e3e3e4',
                            fontWeight: 'normal',
                            fontSize: '12',
                        }
                    }
                }],
            series: [{
                name: '产值增速',
                type: 'bar',
                yAxisIndex: 0,
                itemStyle: {
                    normal: {
                        show: true,
                        color: new echarts.graphic.LinearGradient(0, 0, 0, 1, [{
                            offset: 0,
                            color: '#267bcb'
                        }, {
                            offset: 1,
                            color: '#02e3ff'
                        }]),
                        borderWidth: 0,
                    },
                    emphasis: {
                        shadowBlur: 15,
                        shadowColor: 'rgba(105,123, 214, 0.7)'
                    }
                },
                zlevel: 2,
                barWidth: '40%',
                data: data,
            },
            {
                name: '',
                type: 'bar',
                xAxisIndex: 1,
                yAxisIndex: 0,
                zlevel: 1,
                itemStyle: {
                    normal: {
                        color: '#103e60',
                        borderWidth: 0,
                        shadowBlur: {
                            shadowColor: 'rgba(255,255,255,0.31)',
                            shadowBlur: 10,
                            shadowOffsetX: 0,
                            shadowOffsetY: 2,
                        },
                    }
                },
                barWidth: '40%',
                data: [30, 30, 30, 30,30, 30, 30, 40,{
                    value :30,
                    //自定义标签样式，仅对该数据项有效
                    label: {},
                    //自定义特殊 itemStyle，仅对该数据项有效
                    itemStyle:{
                        // color:'#d9761b',
                        borderColor: '#fb8c07',
                        borderWidth: 1,
                        borderType: 'dotted',
                    },
                    // label: {
                    //     show: true,
                    //     position: 'top',
                    //     formatter: '预测值',
                    //     textStyle:{
                    //         color:'#d9761b',
                    //         fontSize:12
                    //     }
                    // },
                },]},
                {
                    name:'增加值增速',
                    type:'line',
                    yAxisIndex: 1,
                    // xAxisIndex: 1,
                    zlevel: 3,
                    symbol: 'none',
                    smooth: true, //是否平滑曲线显示
                    // stack: '增加值增速(%)',
                    data:dataline,
                    // lineStyle:{
                    //     color:'#ffba27'
                    // },
                    itemStyle: {
                        normal: {
                            show: true,
                            color:'#ffba27',
                            borderWidth: 0,
                        },
                        emphasis: {
                            shadowBlur: 15,
                            shadowColor: 'rgba(105,123, 214, 0.7)'
                        }
                    },
                },
                {
                    name:'增加值增速',
                    type:'line',
                    yAxisIndex: 1,
                    // xAxisIndex: 1,
                    zlevel: 3,
                    symbol: 'none',
                    smooth: true, //是否平滑曲线显示
                    // stack: '增加值增速(%)',
                    data:datalinedotted,
                    lineStyle:{
                        color:'#ffba27',
                        type:'dotted'
                    }
                }
            ]
        }