I read last week that over 2/3 of the divorces filed are by women.
I think much of that has to do with the psychological difference between the two genders. Men, for the most part, tend to only leave a marriage when they have somewhere to go to (i.e. another woman). Women on the other hand can feel incredibly alone even within a marriage, and once they get to that point then they may leave. The leaving is because they already see themselves as entirely alone, so why not actually be alone?
At least that's the insight I took from "How to Save Your Marriage Without Talking About It". It's also the insight that got me to start seeing my W as having already left our M, rather than contemplating it.
Married 6 together 8 Me:38 W:31 second marriage for both SS12, SD10, S6 Bomb: 9/8/11 (day before our 5 yr ann) W moved out: 2/18/12 D final: 11/12/12 Share S 50/50. Spend as much time as I can with SS & SD