Fetch the stats when the stats page is mounted

src/client/components/TheStatisticsPage.vue

@@ -113,7 +113,11 @@ const plotConfig = {
   responsive: true
 }
 
-onMounted(() => {
+onMounted(async () => {
+  if (!statistics.value) {
+    await store.getStatistics()
+  }
+
   buildSpeciesPlot()
   buildSourcesPlot()
   buildHeavySegmentsPlot()