http://online.wsj.com/article/SB10001424127887323375204578270053387770718.htmlThe fertility rate is the number of children an average woman bears over the course of her life. The replacement rate is 2.1. If the average woman has more children than that, population grows. Fewer, and it contracts. Today, America's total fertility rate is 1.93, according to the latest figures from the Centers for Disease Control and Prevention; it hasn't been above the replacement rate in a sustained way since the early 1970s.
The 2020 census might show an even smaller growth figure than the historically low 2010 census.
