This is fun, I gave it a try too!
The same thing happened to me - i prefer more names the farther back in time I go. I guess because the names from my and my mom's generation are pretty boring and tired for me.
1937:
Marie,
Helen,
June,
Betty,
Marion,
Frances,
Nancy,
Irene,
Alice,
Sylvia,
Rose,
Edith,
Dorothy,
Marjorie,
1959:
Cynthia,
Darlene,
Judith,
María,
Anna
1983:
Amy,
Natasha,
Melanie,
Julia
I know my great grandmother's birth year, but my country didn't keep records like this until 1920 apparently.