Could I get a citation for a life expectancy statistic?

I have a tendency to quote “interesting” statistics from time to time. And, while I’ll admit that I have been known to make something up from time to time, I like to be able to cite a source for some particularly noteworthy factoids. I came across a statistic that I am dying to use in conversation sometime but I will not use this one without a reasonable citation. Does anyone know the source of: **“Of all the people in history that have reached 65 years of age, half of them are living right now.” **

Even if that statement were true I think it is far less interesting than it seems at first glance. It is far more likely to be attributable to the fact that the world population only hit one billion around 200 years ago, hit 2 billion less than a century ago, and is at almost 6.7 billion today.

Don’t use it because it probably isn’t true. It is only barely plausible given what we know and it couldn’t be proven even if it were true.

This is just a variation of the 'X percent of people who have ever lived are alive today" and that is almost always wildly incorrect as stated. There are about 7 billion people alive today but somewhere over 100 billion people ever born. People live longer today in general but there have always been people around that lived to be 65 and beyond especially among the recently deceased generations. There may be a greater proportion of people over 65 alive today than at any time in the past but the vast difference in size between those who are alive today and who have already died is so big that I have a hard time believing the factoid as you stated.

http://answers.google.com/answers/threadview/id/703709.html