fix #287 by using simple division

src/views/Discover/Performance/index.vue

@@ -146,6 +146,8 @@ import { setLineChartData } from '@/module/setChartData.js';
 import { simpleTimeLabel, followTimeLabel, dateLabel,
   setTimeStringFormatBaseOnTimeDifference,
   mapTimestampToAxisTicksByFormat,
+  getStepSizeOfYTicks,
+  getYTicksByIndex,
  } from '@/module/timeLabel.js';
 
 const knownScaleLineChartOptions = {
@@ -394,8 +396,9 @@ export default {
           };
           primeVueSetOption.scales.x.min = minX;
           primeVueSetOption.scales.x.max = maxX;
+          const {resultStepSize: YTickStepSize, unitToUse} = getStepSizeOfYTicks(maxY); // Stepsize only needs to be calculated once
           primeVueSetOption.scales.y.ticks.callback = function (value, index, ticks) {
-            return getFollowTimeLabel(value, maxY, 1)
+            return getYTicksByIndex(YTickStepSize, index, unitToUse); 
           };
           break;
         case 'count':