According to the declassified Soviet archives, during 1937 and 1938, the NKVD detained 1,548,366 victims, of whom 681,692 were shot - an average of 1,000 executions a day (in comparison, the Tsarists executed 3,932 persons for political crimes from 1825 to 1910 - an average of less than 1 execution per week).
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Some experts believe the evidence released from the Soviet archives is understated, incomplete, or unreliable.
[65][66][67][68] For example,
Robert Conquest suggests that the probable figure for executions during the years of the Great Purge is not 681,692, but some two and a half times as high. He believes that the KGB was covering its tracks by falsifying the dates and causes of death of rehabilitated victims.
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Historian
Michael Ellman claims the best estimate of deaths brought about by Soviet repression during these two years is the range 950,000 to 1.2 million, which includes deaths in detention and those who died shortly after being released from the Gulag as a result of their treatment in it. He also states that this is the estimate which should be used by historians and teachers of Russian history