fix

backend/src/helpers/convert.ts

@@ -32,8 +32,8 @@ export let add_values = (values) => {
   for (let v of values) {
     for (let key of Object.keys(v)) {
       if (!x[key]) x[key] = 0;
-      x[key] += v[key];
-      x[key] = parseFloat(x[key].toFixed(3));
+      x[key] += v[key] ? v[key] : 0;
+      x[key] = x[key] ? parseFloat(x[key].toFixed(3)) : x[key];
     }
   }
   x = get_change(x);