officially non-accounted child mortality in 1933 at 150,000, leading to a calculation that the number of births for 1933 should be increased from 471,000 to 621,000 (down from 1,184,000 in 1927). Given the decreasing birth rates and assuming the natural mortality rates in 1933 to be equal to the average annual mortality rate in 1927–1930 (524,000 per year), a natural population growth for 1933 would have been 97,000 (as opposed to the recorded decrease of 1,379,000). This was five times less than the growth in the previous three years (1927–1930). Straight-line extrapolation of population (continuation of the previous net change) between census takings in 1927 and 1936 would have been +4.043 million, which compares to a recorded −538,000 change. Overall change in birth and death amounts to 4.581 million fewer people but whether through factors of choice, disease or starvation will never be fully known. In the 2000s, there were debates among historians and in civil society about the number of deaths as Soviet files were released and tension built between Russia and the Ukrainian president Viktor Yushchenko. Yushchenko and other Ukrainian politicians described fatalities as in the region of seven to ten million. Yushchenko stated in a speech to the United States Congress that the Holodomor "took away 20 million lives of Ukrainians,". Former Canadian Prime Minister Stephen Harper issued a public statement giving the death toll at about 10 million. Some Ukrainian and Western historians use similar figures. Historian David R. Marples gave a figure of 7.5 million in 2007. During an international conference held in Ukraine in 2016, Holodomor 1932–1933 loss of the Ukrainian nation, at the National University of Kyiv Taras Shevchenko, it was claimed that during the Holodomor 7 million Ukrainians were killed, and in total, 10 million people died of starvation across the USSR. However, the use of the 7 to 20 million figures has been criticized by historians Timothy D. Snyder and Stephen G. Wheatcroft. Snyder wrote: "President Viktor Yushchenko does his country a grave disservice by claiming ten million deaths, thus exaggerating the number of Ukrainians killed by a factor of three; but it is true that the famine in Ukraine of 1932–1933 was a result of purposeful political decisions, and killed about three million people." In an email to Postmedia News, Wheatcroft wrote: "I find it regrettable that Stephen Harper and other leading Western politicians are continuing to use such exaggerated