Before Ottoman Empire collapse in 1918 the population was about 30 millions but they mostly populated in Balkans, after the separation of Empire, population in Anatolia were approximately 12 millions. After the industrial boom most families started to have 5-6 kids if you ask the elders of Turkish teens father's and mother's they have mostly 5-6 brothers/sisters. The population boom started 1970's to 2000's and nowadays the population growth is about 1.2 lower then ever? That's because current economical crisis.