add percent format

app/javascript/submission_form/area.vue

@@ -643,6 +643,10 @@ export default {
         return new Intl.NumberFormat('de-DE').format(number)
       } else if (format === 'space') {
         return new Intl.NumberFormat('fr-FR').format(number)
+      } else if (format === 'percent') {
+        return `${number}%`
+      } else if (format === 'percent_space') {
+        return `${String(number).replace('.', ',')} %`
       } else {
         return number
       }