FACT: It is estimated that over 85 million people live in the vast country of Ethiopia.  Regarding age structure in this country, only about 3% of the population is over the age of 65.  In the US, about 13% fall into the 65 and older category.

This leaves about 46% of the population ranging between the ages of 0-14, and 51% between 14-64, with a median age of 17 years old in Ethiopia.  In the US the median age of the population is 35 years old.

The high rate of HIV/AIDs and the spread of other infectious diseases, in combination with minimal health services, is a major cause to the youthful demographic in Ethiopia.

Fact found from CIA Factbook.