diff --git a/app/service/result_service_v2.py b/app/service/result_service_v2.py
index 138af267a5d5629711310de115abe33997ba996a..85f6835c6238f806d5c8218161c2729b0bb35886 100644
--- a/app/service/result_service_v2.py
+++ b/app/service/result_service_v2.py
@@ -326,7 +326,7 @@ class UserCustomerResultAdaptor(UserCustomerDataAdaptor):
         now_year = self.end_date.year
         month_return_data_dict = {}
         for i in range(now_year-start_year+1):
-            month_return_data_dict[start_year+i] = {j+1: {"profit": "-", "net_amount": "-"} for j in range(12)}
+            month_return_data_dict[str(start_year+i)] = {str(j+1): {"profit": "-", "net_amount": "-"} for j in range(12)}
         for d_index, d_row in month_sum.items():
             cur_year = str(int(d_index[:4]))
             cur_month = str(int(d_index[5:]))