Every three days would be good going. Like the size of anglers' fish we will never know the truth.
I don't think frequency has a great deal to do with how many children you have so cannot be implied. There are so many other factors involved including the man and woman's fertility that two couples having sex every three days versus every three weeks could end up with the same number of children. The only thing you can say for sure is that a large number of families with 2 or 3 children after 15 years shows something is amiss in that population.
I was just going to say that you're giving a bit too much information about your life there, Greg. Hahaha
As always, there are some elements of your post that I agree with. For example, the ridiculous assertion of hedonistic worldlings that if you have a large family, you must have an above-average amount of sex. Do they not understand how conception happens? The hedonistic modern world is sex-obsessed. And in this case, it doesn't even make sense.
But on the other hand, I'd like to point out that some couples are different from you and your wife, and some Catholic families are nothing like yours.
Our family doesn't EVER deal with late night conference calls or business trips, for example.
Testosterone (and energy level in general) depends a lot on one's genetics, diet, and habits. Some men have real issues with T even their early 20's (just look at the crew at Buzzfeed. Talk about a bunch of soy-boy low T beta males!) but some men have no issues at all in their 40's or older.
Testosterone requires cholesterol (read: MEAT) and strenuous use of muscles causes men to produce more of it. Also, obesity KILLS men in this department.