diff --git a/dsmr_stats/services.py b/dsmr_stats/services.py
index 95af4e6b..9e6ad5d5 100644
--- a/dsmr_stats/services.py
+++ b/dsmr_stats/services.py
@@ -260,7 +260,10 @@ def clear_statistics() -> None:
 
 def electricity_tariff_percentage(start: date, end: date) -> Optional[Dict]:
     """Returns the total electricity consumption percentage by tariff (high/low tariff)."""
-    totals = DayStatistics.objects.filter(day__gte=start, day__lte=end,).aggregate(
+    totals = DayStatistics.objects.filter(
+        day__gte=start,
+        day__lte=end,
+    ).aggregate(
         electricity1=Sum("electricity1"),
         electricity2=Sum("electricity2"),
     )