When I drove trucks, I went to a lot of Asian massage parlours (their showers were WAY cleaner than most truck stops I was at, and being washed is a great way to deal with road weariness), and I found 3 ticklish women. 3 out of several dozen. One said I could tickle her for $180 (and that after the $40 to get in). Not happening. One was mildly, sorta cutely ticklish, and one was fantastically ticklish. Especially the small of her back.
Escorts....probably half of them have been worth it. I've tickled 4 mistresses and all were ticklish to varying degrees. Actually seen two get into a tickle fight as they were tickling me. That was interesting.
The rest of the population, I can only give you the percentage of the women I've tickled. Probably about 3/4. There's something along the lines of 3 billion women tho I'd love to test for you, tho 😉
Christopher