The average age for first-time marriers is 32 for men and 30 for women in England, beetlejizz why would you think over thirty means it's more likely to be a second marriage?
I know it's a regional thing but I'm 30 and don't know anyone who's gotten married in my friendship circle so far. A couple of them are engaged but with no date set to wed.
It's quite rare to marry before 30 these days.
Because the older you get, the more likely it is to be a second marriage simply because people can't marry before 18. Or 16 with parental permission. And older people are more likely to have been married before.
So for example, given that you need to be married 1 year to divorce, 0% of 16 year olds marrying will be second timers. There is a cohort in the under 30 marriage group who couldn't possibly be second timers, so they affect the stats, whereas that's not the case for people over 30. That 0% figure isn't the same for 30 year olds, or 40 year olds, or anyone older. And eg the percentage of 80 year olds who've never married is quite small, so 80 year olds marrying are much more likely to have been married before. More so than 30 year olds marrying.
This is not the same thing as saying that a significant percentage of marriages of people in their early 30s will be second timers. Just that it will be higher than marriages of people who are in their early 20s and the percentage tends to climb the older people get.
Also, it's not quite rare to marry before 30. Think about those stats. If the average age for women to marry is 30, how likely is it that few enough women marry before 30 for it to be considered rare?