This method of estimating period divorce rates, which I got from this old Sam Preston paper (https://journals.sagepub.com/doi/abs/10.1177/004912417500300405), combines mortality rates and death rates to project how many people are lucky enough to die before divorcing at current rates. (Hence “multiple-decrement,” the demographers’ dry way of saying, “there are only two ways out of this.”) When he applied the method, with much cruder data from 1973, incidentally, he got a 43% divorce rate, which was much higher than the rates floating around at the time, and would have made big news in the blogosphere if there had been one. See more writeup and reaction to earlier versions of this analysis here: https://familyinequality.wordpress.com/2016/06/08/life-table-says-divorce-rate-is-52-7/ If you want to cite this in a published source, I have used the numbers in my book: Cohen, Philip N. The Family: Diversity, Inequality, and Social Change, 3rd edition (WW Norton, 2020).