The Russian Empire census, formally the First general census of the population of the Russian Empire in 1897, was the first and only nation-wide census performed in the Russian Empire. The census recorded demographic data as of 9 February 1897 [O.S. 28 January]; with a population of 125,640,021, it made Russia the world's third-most populated country at the time, after the British and Qing empires. Although the census was performed in most of the empire, no enumeration was done in the Grand Duchy of Finland. The census revealed the social class, native language, religion, and profession of citizens, which were aggregated to yield district and provincial totals. The data processing took eight years; publishing the results began in 1898 and was completed in 1905. In total, 119 books in 89 volumes were published for 89 governorates in the empire, including a two-volume summary. The next census had been planned for December 1915, but was cancelled due to World War I. It was not rescheduled before the Russian Revolution. The next census in Russia only occurred at the end of 1926, almost three decades later. Source: Wikipedia (en)