Some historians claim that the death toll was around 20 million based on their own demographic analysis and from dated information published before the release of the reports from the Soviet archives.[60] American historian Richard Pipes noted: "Censuses revealed that between 1932 and 1939—that is, after collectivization but before World War II—the population decreased by 9 to 10 million people.[61] In his most recent edition of The Great Terror (2007), Robert Conquest states that while exact numbers may never be known with complete certainty, at least 15 million people were killed "by the whole range of Soviet regime's terrors".[62] Rudolph Rummel in 2006 said that the earlier higher victim total estimates are correct, although he includes those killed by the government of the Soviet Union in other Eastern European countries as well.[63][64] Conversely, J. Arch Getty, Stephen G. Wheatcroft and others insist that the opening of the Soviet archives has vindicated the lower estimates put forth by "revisionist" scholars.[65][66] Simon Sebag Montefiore in 2003 suggested that Stalin was ultimately responsible for the deaths of at least 20 million people[67]