The population of Latvia today is estimated at 1.9m, slightly below the 1.95m census population of 1935 and substantially below an estimated pre-WWI population of around 2.5m in 1914. It peaked at a high of around 2.7m in 1989 and has been falling steadily since ([WP][1], citing the Latvian statistical bureau). The 1914 figure is before independence from the Russian Empire and may reflect a slightly different set of borders. The 1935 figure is calculated on contemporary borders, though there was a [small realignment in 1944][2] which ceded a town and its hinterland to Russia, where it remains under the modern boundaries. The boundaries thus aren't *exactly* comparable to today.

Many Baltic and Eastern European states show a similar pattern, but none quite match your 1950 cut-off. Estonia and Lithuania have had a similar but less pronounced population decline since peaks around 1990, and the last time they had their current populations was probably circa 1965-70. Hungary's population now is comparable to its population in the mid-1950s. In the Balkans, Bosnia & Herzegovina and Serbia have populations now comparable to their populations in the late 1960s. All of these are still falling gradually.


  [1]: https://en.wikipedia.org/wiki/Demographics_of_Latvia
  [2]: https://en.wikipedia.org/wiki/Territorial_changes_of_the_Baltic_states#Latvia