I have a female colleague (almost my age) who enjoys sex like few others. I've never had sex with her though (because we work together), but she is always telling me about her exploits. Without getting into too much detail, she has provided proof so I know she is not full of shit.
Anyway, she is a good window because she will tell me anything and knows what her female friends say when men are not around. Most women her age absolutely hate sex. They just dole it out to their husbands when necessary. And some have stopped altogether. Most women throttle back the sex after they've had enough kids to "cement" the marriage. A lot of them were not even sure that they liked sex when they were younger, even though they did get horny from time to time. But they mostly pretended to like sex to get husbands, BFs, manipulate men into doing this or that, etc. She says maybe 5% of women really love sex, and that may even be an overestimate; but its low single digits. What she tells me does not surprise me in the least and largely tracks with my experience and gut.
I know, at least when they are younger, women do have sexual urges. This is from my experience with one night stands. Those are situations where women have absolutely nothing to gain and would not do it unless they were very horny. However, as they age, the horniness gets less frequent. After menopause, it can disappear all together. So its all tied to their biological clock (again, no surprise).
My friend's observations apply mostly to White, Black and Asian-American women. I think native Asian women do like sex more than White women, but I would be surprised if their genuine threshold breaks 10%. And the acid test is to see what they do after you marry them; often 5-10 years after. As a wise man once opined: Eventually, all pussy turns rancid.