Trends in naming...

Did a bit of random blog surfing there. Came across a really quite astounding statistic.

If you tally up all the names given to baby boys (in the USA) in 1906 and plot the data according to the last letter of the first name, it looks like this:

Do the same in 1956 and it looks a little different:

But do the same in 2006 and the result is utterly different:

Whoa! What's all that about? Why is 'n' such a popular letter?