For the first census of the Russian Empire in 1897, the famous chemist Dmitri Mendeleev made a long-term forecast of Russia's demographic development, according to which the population of Russia at the end of the twentieth century would be about 0.6 billion people, and by the mid-twenty-first century, it would be more than a billion people. By 1913, the population of the Russian Empire was already 7.8 % of the world's one-and-a-half billion population. However, during the First World War, Communists seized power in Russia and Mendeleev's predictions were not justified because communists...