Fair enough. I have removed that part of the post.
"Percentage of marriages that end in divorce" is an underspecified concept. There is only "percentage of marriages that end in divorce after n years".
According to this NYT article, it is incredibly common to report (new divorces / new marriages) as the "% of marriages ending in divorce" – and this is misleading because it makes a decline in marriages look like an increase in the probability of divorce. The very large figures, like 50% or above, seem to be indeed reporting this figure.
You could adjust for changing demographics of course, but one... (read more)