I'll include 1 year older as I never went to a school more than 2 years, as in we moved and where we moved consolidated several schools for 5th and 6th in the big one and after that all our high schools were split, Junior down town, then we had an Intermediate for 9th and 10th, then Senior high school. I'll have to remember those who weren't actual friends...
11 within my 0.3 mile road in a 70's suburban neighborhood. Those are just the ones my age and a year older. Doesn't include all their older siblings or the younger ones which were my brother's age.
The school bus had 2 stops in my neighborhood and it was packed full (for 2 grades only mind you.) There were so many kids as the neighborhood wasn't very big at all.
Today I visit my mother and you don't see a single kid outside. They are there, I have seen them getting in and out of cars and into the house. Not nearly as many as when I was a kid though.