He got it from here: <A HREF="http://silentrunning.tv/archives/003696.php" target="_new">http://silentrunning.tv/archives/003696.php</A> <A HREF="http://www.worldbank.org/data/databytopic/POP.pdf" target="_new">http://www.worldbank.org/data/databytopic/POP.pdf</A> <A HREF="http://www.usc.edu/dept/MSA/introduction/woi_history.html#12" target="_new">http://www.usc.edu/dept/MSA/introduction/woi_history.html#12</A>