echarts堆叠图，数据变化不大的情况下，如何设置趋势变化明显一点？

Question

echarts堆叠图，数据变化不大的情况下，如何设置趋势变化明显一点？现在趋势变化不明显？有哪些方案呢？

option = {
  title: {
    text: 'Stacked Line'
  },
  tooltip: {
    trigger: 'axis'
  },
  legend: {
    data: ['Email', 'Union Ads', 'Video Ads', 'Direct', 'Search Engine']
  },
  grid: {
    left: '3%',
    right: '4%',
    bottom: '3%',
    containLabel: true
  },
  toolbox: {
    feature: {
      saveAsImage: {}
    }
  },
  xAxis: {
    type: 'category',
    boundaryGap: false,
    data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
  },
  yAxis: {
    type: 'value'
  },
  series: [
    {
      name: 'Direct',
      type: 'line',
      stack: 'Total',
      data: [32.21, 32.23, 32.56, 32.19, 32.33, 32.3, 32.5]
    },
    {
      name: 'Search Engine',
      type: 'line',
      stack: 'Total',
      data: [34.41, 34.45, 34.40, 34.41, 34.47, 34.49, 34.45]
    }
  ]
};

代码粘贴下面链接可看到结果：
https://echarts.apache.org/examples/zh/editor.html?c=line-stack

Answer 1

用 2套 Y轴
一套 的坐标数值范围改成 30 - 40
另一套 坐标数值范围改成 60 - 70