unintended commit
diff --git a/superset-frontend/plugins/plugin-chart-echarts/src/Histogram/transformProps.ts b/superset-frontend/plugins/plugin-chart-echarts/src/Histogram/transformProps.ts
index 28d2a93..388e79a 100644
--- a/superset-frontend/plugins/plugin-chart-echarts/src/Histogram/transformProps.ts
+++ b/superset-frontend/plugins/plugin-chart-echarts/src/Histogram/transformProps.ts
@@ -84,7 +84,7 @@
     .filter(key => !groupbySet.has(key))
     .map(key => {
       const array = key.split(' - ').map(value => parseFloat(value));
-      return `${xAxisFormatter(array[0])} - ${xAxisFormatter(array[1])}`;
+      return `${xAxisFormatter(array[0])} '-' ${xAxisFormatter(array[1])}`;
     });
   const barSeries: BarSeriesOption[] = data.map(datum => {
     const seriesName =