Thanks Dave,

I'm basing my comments on the assumption that the present data for those countries in the developed world where contraception and abortion are relatively commonly used would influence the current birth rate. There would be less births in those countries than in countries where contraception and/or abortion are forbidden or not accepted socially, i.e. where births would occur naturally without intervention prior to or after conception.

I tried to find a graph to check whether China's one child policy had an obvious effect on the population increase rate but maybe I didn't look in the right places. I'll keep looking.

I'm not fixed on finding the answers I want. I just want to find real facts.