 Complete the following phrase:  A 20th-century Turkish professor, İbrahim Hakkı Akyol, also considers the 1844 as an underestimation of the total Ottoman population because the taxes to be set for each vilayet and kaza would be based on the census result, and the population wanted to avoid them. In 1867, the 2.4 million figure remains unchanged, and was used by Ottoman official Salaheddin Bey in a book published on the occasion of the 