This is really interesting: a divorce calculator. I worked out the likelihood of TOH and I having got divorced if we'd got married in the first three years of our relationship. Apparently, 47% of all people of the same age and "similar social background" (whatever that means - they just asked me my level of education and whether we had children) are already divorced, and 21% will get divorced in the next five years.
It's an obvious point, made time and time again, but given that most straight people don't treat marriage as sacred, why on earth do they care about gay people denigrating the institution? These figures make it even more obvious. They also make it clear that forcing people to get married earlier and earlier in order to have sex (because people are guilted into thinking they should only have sex with their one and only spouse but also get really rather randy in their teens/early twenties) really does nothing to ensure the success of the marriage. I then calculated our chances if we'd married at 23/24 (rather than under 22) - that would lower the divorce rate to just over a third.
Or, on the other hand, you could just wait until the day you get married to first exchange saliva with your other half.