Those statistics are totally the wrong ones to look at. It's "Age at marriage for those who divorce in America". You want "Divorce rate by age at marriage".
"Divorce rate by age at marriage" + the age of marriage as a percentage of all marriages (otherwise you might find 80% of marriages at age 60 are successful but fail to realize that probably accounts for a <1% of all marriages).
I think it's kind of funny that we're all seeking statistics on marriage. Where are the romantics on HN?