Ethnic Russians in post-Soviet states
After the dissolution of the Soviet Union (USSR) in December 1991, about 25 million ethnic Russians in post-Soviet states found themselves living outside of Russia. However, this number declined to less than 6 million today, excluding Ukraine in which ethnic Russian population is hard to estimate due to lack of a recent census.
Source: Wikipedia — Ethnic Russians in post-Soviet states (CC BY-SA 4.0)