Honestly, every time I see names aka Trixi, Trixy, Trixie or any other variations - I immediately remember this scene and just can't stop laughing:
I think "Lucifer" just ruined this name for me
Well, since we started talking about actual numbers.
I made some transposing magic and used few formulas, so out of 162 games in my DB with LI lists (only lewdable characters - 1526 names in total), here are the results:
Of course I didn't consider different variations of names, I only did it for Bella/Isabella.
EDIT: Also there games where we actually don't know girls names - like ToUV, so they are called in my list as girl 1, girl 2, or brothel girl 1, brothel girl 2 etc etc