Excessive MySQL time

My web site’s MySQL daily time exploded in December. I tried a lot of things to no avail so I started deactivating one plug in at a time. At that time WP Statistics plug in had not been tested with the latest WP version. When I deactivated WP Statistics plug in, MySQL daily time went back to normal. I uninstalled the plug in and reinstalled when it was compatible with the latest WP version. MySQL daily time shot up again so I had no choice but to deactivate WP Statistics plug in.