Population of Czechoslovakia 1910-1990

In the early twentieth century, modern-day Czechia and Slovakia were united, as a part of the Austro-Hungarian Empire until after World War I. It then became an independent state in 1918, although the borders did change during this time and after the Second World War, until it peacefully dissolved into the both Czechia and Slovakia in 1993.
The population of Czechoslovakia did not grow significantly between 1910 and 1921, and in regards to gender the male population actually decreased by around 50 thousand. The population drastically decreases from 1930 to 1946/7, from 14.7 to 12.2 million people. These changes are mostly as a result of both World Wars, mass displacement of ethnic Germans following WWII, and the rearranging of Czechoslovakia's borders. After 1946/7 the population grows quite gradually, and is almost reaches it's pre-WWII height again in 1970, with 14.35 million people.