So as a child of the late seventies, I wondered why there were always about 3-4 Matts in my school classes growing up. It turns out that in the seventies, Biblical names, and particularly those of the New Testament, were pretty popular:
It appears that these are all on the decline, perhaps as people have moved away from religion in general.
I found this to be the case on most of the Biblical names I tried:
The anomalies were Noah, Samuel, Levi, Jonah, Isaac, and Luke: