diff --git a/sql/query_stat_cpu_time.sql b/sql/query_stat_cpu_time.sql
index fa4328e..adbd0e3 100644
--- a/sql/query_stat_cpu_time.sql
+++ b/sql/query_stat_cpu_time.sql
@@ -10,38 +10,37 @@ group by query
 )
 
 SELECT
-(100*total_time/(SELECT t FROM s))::numeric(20,2) AS time_percent,
-(100*(blk_read_time+blk_write_time)/(SELECT iot FROM s))::numeric(20,2) AS iotime_percent,
-(100*(total_time-blk_read_time-blk_write_time)/(SELECT cput FROM s))::numeric(20,2) AS cputime_percent,
+(100*total_time/NULLIF((SELECT t FROM s), 0))::numeric(20,2) AS time_percent,
+(100*(blk_read_time+blk_write_time)/NULLIF((SELECT iot FROM s), 0))::numeric(20,2) AS iotime_percent,
+(100*(total_time-blk_read_time-blk_write_time)/NULLIF((SELECT cput FROM s), 0))::numeric(20,2) AS cputime_percent,
 total_time::numeric(20,2) as total_time,
-(total_time*1000/calls)::numeric(20,2) AS avg_time,
-((blk_read_time+blk_write_time)*1000/calls)::numeric(20,2) AS avg_io_time,
+(total_time*1000/NULLIF(calls, 0))::numeric(20,2) AS avg_time,
+((blk_read_time+blk_write_time)*1000/NULLIF(calls, 0))::numeric(20,2) AS avg_io_time,
 calls,
-(100*calls/(SELECT s FROM s))::numeric(20,2) AS calls_percent,
+(100*calls/NULLIF((SELECT s FROM s), 0))::numeric(20,2) AS calls_percent,
 rows,
-(100*rows/(SELECT r from s))::numeric(20,2) AS row_percent,
+(100*rows/NULLIF((SELECT r from s), 0))::numeric(20,2) AS row_percent,
 query
 FROM _pg_stat_statements
 WHERE
-(total_time-blk_read_time-blk_write_time)/(SELECT cput FROM s)>=0.02
+(total_time-blk_read_time-blk_write_time)/NULLIF((SELECT cput FROM s), 0)>=0.02
 
 UNION all
 
 SELECT
-(100*sum(total_time)/(SELECT t FROM s))::numeric(20,2) AS time_percent,
-(100*sum(blk_read_time+blk_write_time)/(SELECT iot FROM s))::numeric(20,2) AS iotime_percent,
-(100*sum(total_time-blk_read_time-blk_write_time)/(SELECT cput FROM s))::numeric(20,2) AS cputime_percent,
+(100*sum(total_time)/NULLIF((SELECT t FROM s), 0))::numeric(20,2) AS time_percent,
+(100*sum(blk_read_time+blk_write_time)/NULLIF((SELECT iot FROM s), 0))::numeric(20,2) AS iotime_percent,
+(100*sum(total_time-blk_read_time-blk_write_time)/NULLIF((SELECT cput FROM s), 0))::numeric(20,2) AS cputime_percent,
 sum(total_time)::numeric(20,2),
-(sum(total_time)*1000/sum(calls))::numeric(10,3) AS avg_time,
-(sum(blk_read_time+blk_write_time)*1000/sum(calls))::numeric(10,3) AS avg_io_time,
+(sum(total_time)*1000/NULLIF(sum(calls), 0))::numeric(10,3) AS avg_time,
+(sum(blk_read_time+blk_write_time)*1000/NULLIF(sum(calls), 0))::numeric(10,3) AS avg_io_time,
 sum(calls),
-(100*sum(calls)/(SELECT s FROM s))::numeric(20,2) AS calls_percent,
+(100*sum(calls)/NULLIF((SELECT s FROM s), 0))::numeric(20,2) AS calls_percent,
 sum(rows),
-(100*sum(rows)/(SELECT r from s))::numeric(20,2) AS row_percent,
+(100*sum(rows)/NULLIF((SELECT r from s), 0))::numeric(20,2) AS row_percent,
 'other' AS query
 FROM _pg_stat_statements
 WHERE
-(total_time-blk_read_time-blk_write_time)/(SELECT cput FROM s)<0.02
+(total_time-blk_read_time-blk_write_time)/NULLIF((SELECT cput FROM s), 0)<0.02
 
 ORDER BY 3 DESC;
-