Sigheh

I just learned about the Shia Muslim tradition of temporary marriage, or sigheh, which allows a man and a woman in Iran to marry for a set period of time, ranging from an hour to 99 years. This is evidently a common thing in Iran where the young men have a hard time finding sufficient work to support a wife and needs to relieve sexual tension. My source did not reveal the average time period requested for sigheh, but I suspect there aren't many 99 year arrangements.