And it isn't always a good ratio!
Yeah LOL.
Marriage, for me, is a bit different. In my humble opinion, just about every normal man and woman was designed for marriage.
It's a mixture of all the things you NEED from an intimate, monogamous, lifetime opposite-gender relationship, with the other half being your primary opportunity to become a person whose life, soul, attention & person is totally given to someone else, in the ultimate selfless devotion that gives us purpose and reminds us we are made in the image of God - to know and serve Him.
Families are SO parallel to many Godly attributes, that's why they work and their brokenness destroys the world in a million ways.
I think almost everyone is best realized by joining the married world, doing so carefully at first, but then with reckless selfless abandon.
But children is a bit different. They come naturally of course, but some people do seem a bit well suited to the childless life. I have an uncle and aunt who are childless by choice, and I can't really judge them for it - they're givers in their own way, and after all, the world does have a lot of kids already!