European Tribune - Community, Politics & Progress.

European Tribune - Community, Politics & Progress.: "For what it's worth, I once calculated 5% of fertile-age women are pregnant at any given time...

Assume 2 children per woman [replacement rate].
Assume 9 months of pregnancy per child [mild assumption]
Assume 30 years of fertile life [15 to 45]

2 pregnancies/woman * 9 months/pregnancy / 30 years/woman = 5%

Coincidentally, 30 years is also the length of the 24-54 age period. "