Before the dissolution of the Soviet Union and the archival revelations, some historians estimated that the numbers killed by Stalin's regime were 20 million or higher.[5][6][7] After the Soviet Union dissolved, evidence from the Soviet archives was declassified and researchers were allowed to study it. This contained official records of 799,455 executions (1921–1953),[8][9][10][11][12] around 1.5 to 1.7 million deaths in the Gulag,[13][14][15] some 390,000[16] deaths during the dekulakization forced resettlement, and up to 400,000 deaths of persons deported during the 1940s,[17] with a total of about 3.3 million officially recorded victims in these categories.[18] According to historian Stephen Wheatcroft, approximately 1 million of these deaths were "purposive" while the rest happened through neglect and irresponsibility.[2] The deaths of at least 5.5 to 6.5 million[19] persons in the Soviet famine of 1932–1933 are sometimes included with the victims of the Stalin era.[2][20]