while the estimated number of underground nuclear tests conducted in the period from 1957 to 1992 is 1,352 explosions with a total yield of 90 Mt. As a result of the 1996 Comprehensive Nuclear-Test-Ban Treaty, there were no declared tests between the 1998 Pakistani Chagai-II and the 2006 North Korean test, and none outside North Korea to date.

Very few unknown tests are suspected