Fix bug: change max_count to max_index to determine x-axis range

app.py

@@ -79,7 +79,7 @@ def get_bar_chart(df):
     last_update_time = max(df["query_time"])
     last_update_time = datetime.fromisoformat(last_update_time).strftime("%Y-%m-%d %H:%M:%S")
 
-    max_count = df["count"].max()
+    max_count = df["index"].max()
 
     fig.update_layout(
         barmode="stack",