It's been a few years since the majority of the world's population shifted to cities. But, of course, this urban majority didn't all happen at once.
A new report out from the Asian Development Bank has a special chapter on "Green Urbanization in Asia." While there's a lot of interesting information there, one chart stood out. As you can see below, this chart tracks the time it has taken for the populations of various parts of the world to go from roughly 10 percent urban to 50 percent urban.