I have a fairly heavily loaded DB that has been facing performance problems with disk IO lately. Have been trying to tune the DB using various parameters, but seems like the write load is still very high. I got the following results from running the select on pg_stat_bgwriter, and am wondering if it is abnormal?

select * from pg_stat_bgwriter;

checkpoints_timed checkpoints_req buffers_checkpoint buffers_clean maxwritten_clean buffers_backend buffers_alloc
7829 39 12538586 1398590

12501 715426 40053158

Seen some literature that the numbers should be lower, but am wondering what I should be seeing for this.