Sorry, but I revealed some very big mistake at your site. Ukrainian language is principal in Ukraine, while at your site Russian reflected as primary and principal ones. Ukrainian is the state language, and all official government and government institutions are obligated to serve people and to communicate with them in Ukrainian. Ukrainian language is only one state language according to constitution. And in accordance with the last surveys and researches up to 70-72% of people say that their native language is Ukrainian.
The status of Russian [rus] in Ukraine as a principle language will be removed in the next edition of the Ethnologue.