According to Wikipedia, there are currently 10 million Mongols whereas Turkic peoples amount to 140-160 million. How did this happen?
Mongolia cannot support a large population of people, most of the area is made up of the steppe which is not arable. Their main source of food is from their lifestock, atleast until the 20th century
Post temporary deleted.
I will update the answer and repost it when I have more time.
My thanks to /u/keyilan for his input on Linguistics that I was not aware of.