Only add in months with activity, skip the rest to save space
diff --git a/server/plugins/messages.py b/server/plugins/messages.py
index e1077ba..ba598ae 100644
--- a/server/plugins/messages.py
+++ b/server/plugins/messages.py
@@ -472,7 +472,8 @@
         oldest = datetime.datetime.fromtimestamp(aggs["first"]["value"] or 0)
         youngest = datetime.datetime.fromtimestamp(aggs["last"]["value"] or 0)
         for bucket in aggs["active_months"].get("buckets", []):
-            monthly_activity[bucket["key_as_string"]] = bucket["doc_count"]
+            if bucket["doc_count"]:
+                monthly_activity[bucket["key_as_string"]] = bucket["doc_count"]
 
     return oldest, youngest, monthly_activity