Why "Ukrainians" can't get along
No single datapoint could capture or explain all of that. But the map below comes perhaps as close as anything could. It shows Ukraine, color-coded by the country's major ethnic and linguistic divisions. Below, I explain why this map is so important and why it helps to tell Ukraine's story. The short version: Ukraine's politics have long been divided into two major factions by the country's demographics. What's happening right now is in many ways a product of that division, which has never really been reconciled
Roughly speaking, about four out of every six people in Ukraine are ethnic Ukrainian and speak the Ukrainian language. Another one in six is ethnic Russian and speaks Russian. The last one-in-six is ethnic Ukrainian but speaks Russian. This map shows where each of those three major groups tend to live. (I'm rounding a bit on the numbers; about five percent of Ukrainians are minorities who don't fit in any of those three categories.)
http://www.washingtonpost.com/blogs/worldviews/wp/2013/12/09/this-one-map-helps-explain-ukraines-protests/