>I imagine most people in the US (and else where) live in structures younger.

my experience living in the U.S is most people live in structures considerably younger, and most places you need to travel to find a house that old (as opposed to a town hall)

places lived in U.S - Midwest and West, traveled through South and East.

My experience living in Europe is most people have lived in a place that is over 100, yes I think the terms young and old are fairly relative, and in much of the U.S a house that is 100+ is old, the house has history and might be preserved as such, whereas in lots of the world that is pretty new stuff and maybe we should tear it down and build something even newer.