Most interesting thing that stands out to me is the number of names that appear to be what I would consider an abbreviation of a more traditional name.
e.g. “Pat” is cited, but doesn’t specify whether that refers to Patricia or Patrick.
Common nicknames eventually just become given names on their own, like "Jack" or "John" or "Alex".
These are presumably from Social Security registrations, so reflecting official given names.
Another interesting analysis would be the movement back and forth between full names and their associated common diminutives.