Django query with aggregation

query.py

    status_counts_by_month = (
        Task.objects.filter(plan_id=plan_id, metric_type=metric_type, group_by_date__year=effective_year)
        .annotate(
            completed_on_time=Case(
                When(completed_date__isnull=True, then=0),
                When(completed_date__lte=F("due_date"), then=1),
                default=0,
                output_field=IntegerField(),
            )
        )
        .annotate(month=ExtractMonth("group_by_date"))
        .values("month")
        .annotate(total=Count("id"), number_completed_on_time=Sum("completed_on_time"))
        .values("month", "number_completed_on_time", "total")
    )