Heap Only Update

I am trying to find tables which Heap only update ratio less then 1 . Then i will decrease fillfactor on these tables  for more speedly update queries.

I am using this query to find hot ratio. For you , this method true or false ?

select relname  from pg_stat_user_tables where  n_tup_upd>0 and n_tup_hot_upd > 0 and n_tup_hot_upd/n_tup_upd::float < 1;

Thanks .

Best Regards.