Approximately 57 percent of all marriages last at least 15 years. However, every marriage is different, just as every individual involved in a marriage is different.
There are many factors which end up impacting a couple's chances, such as their age at the time of their wedding, their finances, their family history and even their education level. That is not to say that any collection of specific circumstances is certain to spell disaster for a marriage, but financial strain is often the most commonly cited motivator behind a divorce. In the end, how long a marriage lasts is entirely dependant on the two people involved in the relationship.