I'd go as far to say most girls around my age are attractive in some way or another, so 5% seems exceptionally fussy!

I've lived in London, and to be honest I found far less than 5% of women my age attractive.

Would be interesting to check this for real, but off the top of my head my estimate would be more like 1% (not for London, but in general).

Although there was this other research that showed that men (maybe also women, can't remember) are very quick to adapt their "demands" to the available offering. That is if at a party, you might settle for someone from the 10% of attractiveness at that party, even if the attractiveness compared to the whole population might be a lot less.