ensure "year" column is integer (no commas)

app.py

@@ -32,6 +32,10 @@ def get_data():
           FROM survey_info;
     """, conn)
     conn.close()
+
+    # Ensure year column is int, show blank instead of NaN
+    if "year" in df_.columns:
+        df_["year"] = pd.to_numeric(df_["year"], errors="coerce").astype("Int64")
     return df_
 
 df = get_data()