I'm gonna give you a comparisson study here:
PRE-MARRIAGE
1. 6-9
2. Some steady, some not, not terribly relevant at that time.
3. I've had sex with about 40 or so women in the past, so I could average about 2 new partners per month.
POST MARRIAGE
1. 6 times per month average. Twice a week, and never during her menstrual cycle week.
2. With my wife of course.
3. I haven't seriously considered ever cheating on my wife.
Now, that said, the overall quality of sex has declined (less passionate, less adventurousness) on her part. That's not to say that there aren't occasions on which it is very hot & spicy (she's still a HB 8.5 afterall), but by comparisson it is less spontaneous and passionate.
On the other hand, what you trade in passion, you (should) make up for in regularity. There's no guess work after marriage. You exchange variety for consistency. Trust me, regarding consistency, it is never what women will sell you on.