The two biggest time frames for divorce are:

1. The first three years of marriage. Understandable, because it might take time being constantly together to realize that it's not doable.

A lot of people don't realize that number 2 is right after the last child has gone to college, or left the home. Often times marriages can survive 15-20 years because of mutual relationships that a mother and father have with their children. Once that common link is gone, it can many times lead to a split.