3 Lies About Jobs and the Unemployment Rate - US News (2012)

Each month, more people join the working age population than retire or die. Consequently, the economy needs to add about 180,000 jobs a month just to keep up with population growth.

http://www.usnews.com/opinion/blogs/economic-intelligence/2012/05/29/3-lies-about-jobs-and-the-unemployment-rate