I don't see any reason to think it follows a bell curve; it has to be skewed way to the right, as it can't be negative. The question you're asking is more-or-l

I don't see any reason to think it follows a bell curve; it has to be skewed way to the right, as it can't be negative. The question you're asking is more-or-less answered in eric4smith's link, on page 6. The answer depends on the year of marriage, and the data is from 2001, so for 20 years of marriage, it can only go up to 1980. The percentage of men whose marriage had lasted at least 20 or 25 years, by year of marriage, was: 20yrs 25yrs 1955 to 1959 76.2 72.3 1960 to 1964 66.1 62.3 1965 to 1969 62.1 58.0 1970 to 1974 55.8 52.9 1975 to 1979 58.4