why timer_stop(1); is different by sum single queries time

For to evaluate time of every query I have used

timer_stop(1);
and
print_r($wpdb->queries);

While the really time is that indicate by timer_stop = 4 second and 26 queries,

the sum of every queries’s time is more different (totally is 0.2 second and not 4 sec)

So print_r($wpdb->queries) that return the singly 26 queries in the shape (write only one with the more high value):
[4] => Array
(
[0] => SHOW TABLES LIKE ‘my_table’
[1] => 0.02332499465942

not said me the really value?
or the value of every query is correct and timer_stop measure than totality sum also others time?
how I can resolve? can to do other tests?