diff --git a/app/db_mgr.py b/app/db_mgr.py
index eaa0c34..d4a2b6d 100644
--- a/app/db_mgr.py
+++ b/app/db_mgr.py
@@ -79,26 +79,28 @@ def charges_by_project_stacked(project_id, category="service"):
     :param category: what dict to build for each period, 'service' or 'capacity' ?
     :return: a 2 dim table with header as first line and datas next, of the form
             period, category_0, category_1, ....., category_n,
-            sem_0, value_00, value_01, ....., value_0n,
-            sem_1, value_10, value_11, ....., value_1n,
+            per_0, value_00, value_01, ....., value_0n,
+            per_1, value_10, value_11, ....., value_1n,
                 .
                 .
-            sem_n, value_n0, value_n1, ....., value_nn,
+            per_n, value_n0, value_n1, ....., value_nn,
     """
     if category == 'capacity':
         category_table = 'capacity'
         sql_req = """
-        select c.charge_rate
+        select sum(c.charge_rate)
         from capacity c1 left join
             charge c on c1.id = c.capacity_id and project_id = {} and period_id={}
+            group by c1.id
         order by c1.id
         """
     elif category == 'service':
         category_table = 'service'
         sql_req = """
-        select c.charge_rate
+        select sum(c.charge_rate)
         from service s left join
             charge c on s.id = c.service_id and project_id = {} and period_id={}
+            group by s.id
         order by s.id
         """
     else:
--
libgit2 0.21.2