In a follow-up to my previous post where I spoke of maternal death rates, I spent a little time searching for a better source (rather than my back of the envelope calculations) for maternal mortality. Historic data for these types of observations is notoriously hard to come by. I ran across a site I had found a while back, Gapminder, that offers a different type of  graphic representation of data. The TED talk, found here, describes the possibilities much better than I can. Here you can create a graph of childhood mortality under 5 and correlate it correlated to family size over time. Do this and consider the year that effective hormonal contraceptive was made available.  Makes for some  interesting observations.