Can't you just pull up an X-Windows calculator or, better yet, whip up a shell script to calculate it?I don't think they are all doomed.. but many of them are. At least in the US. I don't have numbers outside of here.
If 50% of all marriages fail and you then add in the number of marriages that don't end in divorce for reasons like staying together for the kids or not having the money to divorce then that number is higher.
Then if you add in all the relationships that fail before they even get to marriage the number of relationships that probably do not fail is probably around 10%.
Just some fuzzy math. Sorry I didn't have time to do all the NERD stuff for you NRITH