The 50% divorce rate is a misleading statistic. Most of that number comes from "repeat offenders" who marry and divorce more than twice. If you break out the multiple sequential marriages, the rate for single divorces is much lower.
Ok. I can agree with that.
Do you know the 'much lower' number for 'single marriage' divorces? How does this figure compare with co-habitation?
So simply put, the question would be:
What percentage of first time marriages succeed compared to first time co-habitations?