Issue #124: Done.

src/components/Discover/Map/Filter/Trace.vue

@@ -146,6 +146,13 @@ export default {
         plugins: {
           legend: { // 圖例
             display: false,
+          },
+          tooltip: {
+            callbacks: {
+              label: (tooltipItems) =>{
+                return `${tooltipItems.dataset.label}: ${tooltipItems.parsed.y}%`
+              }
+            }
           }
         },
         animations: false,