minor fix

app.py

@@ -42,7 +42,7 @@ df["author"] = df["author"].apply(lambda x: clickable(x))
 df['Total Usage'] = df[['models', 'datasets', 'spaces']].sum(axis=1)
 df = df.sort_values(by='Total Usage', ascending=False)
 
-sum_all_author = naturalsize(sum(merged_df['models'].tolist()+merged_df['datasets'].tolist()+merged_df['spaces'].tolist()))
+sum_all_author = naturalsize(sum(df['models'].tolist()+df['datasets'].tolist()+df['spaces'].tolist()))
 
 naturalsize_columns = ['Total Usage', 'models', 'datasets', 'spaces']
 df[naturalsize_columns] = df[naturalsize_columns].applymap(naturalsize)