[Fix] Balance sheet not working (#10311)

diff --git a/erpnext/accounts/report/financial_statements.py b/erpnext/accounts/report/financial_statements.py
index b6c4fd2..d81c1eb 100644
--- a/erpnext/accounts/report/financial_statements.py
+++ b/erpnext/accounts/report/financial_statements.py
@@ -234,7 +234,7 @@
 			for period in period_list:
 				total_row.setdefault(period.key, 0.0)
 				total_row[period.key] += row.get(period.key, 0.0)
-				row[period.key] = ""
+				row[period.key] = 0.0
 
 			total_row.setdefault("total", 0.0)
 			total_row["total"] += flt(row["total"])