Moreover, the population in this region is older than the rest of the world and their older population skews more heavily female. Additionally, young men in the former Soviet Union have "an unusually high mortality rate," according to Pew.
At the other end of the spectrum, the data in many countries is skewed by policies and practices that harm women at a greater rate than men, like China's One Child Policy and similar practices in India, to name just a couple examples.
It's an interesting look at the world. But before you go making the obligatory "My dating life is sooo terrible that I'm moving to X" joke, note that this is a broad look at populations and doesn't account for age or trends. So, make the joke, but in practice, you're it probably wouldn't make a difference.