The scale of the echarts Y axis corresponds to the data

var xAxisData = [ ' 2018-01 ' , ' 2018-02 ' , ' 2018-03 ' , ' 2018-04 ' , ' 2018-05 ' , ' 2018-06 ' , ' 2018-07 ' , ' 2018-08 ' , ' 2018-09 ' , ' 2018-10 ' , ' 2018-11 ' , ' 2018-12 ' ];
var legendData = [ 'Complaint volume ' , ' resolution volume ' , ' complaint resolution rate ' ];
 var title = " Multi-horizontal line chart " ;
 var serieData = [];
 var metaDate = [
    [120, 140, 100, 120, 300, 230, 130, 170,140, 120, 300, 230],
    [200, 120, 300, 200, 170, 300, 200, 180,200, 190, 300, 200],
    [100,200, 140, 300, 200, 180, 100, 300, 230, 130, 100 ,300,]
]
for ( var v = 0 ; v <legendData.length; v ++ ) {
     var series = {
        name:legendData[v],
        type: 'line',
        symbol:"circle",
        symbolSize:10,
        date: metaDate [v]
    };
    seriesData.push (series)
}
var colors = ["#036BC8","#4A95FF","#5EBEFC","#2EF7F3","#FFFFFF"];
var option = {
    backgroundColor: '#0f375f',
    title : {text: title,textAlign:'left',textStyle:{color:"#fff",fontSize:"16",fontWeight:"normal"}},
    legend: {
        show:true,left:"right",data:legendData,y:"5%",
        itemWidth:18,itemHeight:12,textStyle:{color:"#fff",fontSize:14},
    },
    color:colors,
    grid: {left: '2%',top:"12%",bottom: "5%",right:"5%",containLabel: true},
    tooltip : { trigger: 'axis',axisPointer : { type : 'shadow'}},
    xAxis: [
        {   
            type: 'category',
            axisLine: { show: true,lineStyle:{ color:'#6173A3' }},
            axisLabel:{interval:0,textStyle:{color:'#9ea7c4',fontSize:14} },
            axisTick : {show: false},
            date: xAxisDate,
        },
    ],
    yAxis: [
        {   
            axisTick : {show: false},
            splitLine: {show:false},
            axisLabel:{textStyle:{color:'#9ea7c4',fontSize:14} },
            axisLine: { show: true,lineStyle:{ color:'#6173A3'}},
        },
    ],
    series: seriesData
};