What is the percentage of teen mothers in the world?

This question simply can't be answered because some unwanted pregnancies are not noted. Often a young unwed mother will be scurried off to a "Home for Unwed Mothers" to an aunt or uncles, or she will run away and try working things out on her own. There is also abortion that is usually not reported. It's certainly true that exact statistics are not possible. However the estimated number (which is for certain low), is 13 million world wide. With the lowest percentage being in S.Korea and one of the highest at almost 70% being Peru.