Where all these amount of money come from ?

Meles Zenawi net worth: Meles Zenawi Asres was the former Prime Minister of Ethiopia who presided over the country from 1995 to his death in 2012. He was also the President of Ethiopia from 1991 to 1995. He was one of the most recent literate and forward thinking leaders of Africa. Zenawi had an MBA from the United Kingdom, and a Masters of science in economics from Netherlands. His net worth currently stands at $3 Billion.

source http://www.therichest.org/celebnetworth/category/politician/minister/