My average was about twice a day when we were first married. Sometime along the way, it has deteriorated to less than twice a week. I'd suspect most people are about the same, though rates and frequencies may vary.
Of course, I never considered the lack of a pregnancy result as a lack of success. Just trying was a whale of a lot of fun.
Your numbers are about the same as I’ve read in several sources (and mirror my own experience as well).
I assume that this bettered the relationship between you and your wife? ;)