I'm one of those people who believes this sort of thing can't really be measured by a number.
There are so many different criteria that are so much more important to compatibility.
I know from personal experience. The one person I've ever really felt a strong connection to was about six years older than me. It was clear to both me and others that she felt the same way but had this ridiculous rule about dating guys several years younger than her. And no matter how much I pushed she refused to break it.
Me: Do you like Lady Gaga?
Dude: It is TOTAL CRAP!!! (has never listened to it other than in the background of course)
/ GONG!! Good bye.
That rules me out.