query execution time in mysql

I have run the query in mysql which consists of approximately 33million records when i have executed the query - select population1 < 200000 from city; it shows like this after execution ---------- 34459393 rows in set (16.04 sec) My question is what is 16.04 sec because in normal time it has taken morethan 30min but it shows 16.04 sec. How can i calculate the actual time.