More than 10 million Ukrainians have fled their country because of Kyiv’s pro-NATO course and the imposition of Ukrainian as the state language. At least those were the headlines of the pro-Kremlin media last week, implying that the country of over 44 million people had lost almost a quarter of its population in just 5 years. [The claim is very far from reality - Ed.]
Ukraine's population declined by about 8 million people throughout 1991-2018, first of all, due to sub-replacement fertility.
The Ukrainian finance ministry provided such data on the Ukrainian population in 2018, noting that the population of the occupied territories (some 2,5 mln people living in Crimea, Sevastopol, certain areas of Luhansk and Donetsk oblasts) was not added to the total figures starting from 2015:
As of 2018, some 2,6 million of Ukrainians were migrants working abroad, mostly at seasonal works.
As for the emigration rate, the Ukrainian statistics service or UkrStat reports that every year more people immigrate to Ukraine and emigrate from it:
