20/80 rule is real (in 19th c. France). Out of 100 young women who married at least 80 regretted it

In his book Les Femmes Qui Tuent, published in 1880, Alexandre Dumas (the younger) mentions that a priest told him in a private conversation that:

"J'ai pu constater que, sur cent jeunes filles dont j'avais fait l'éducation religieuse et qui se mariaient, il y en avait au moins quatre-vingts qui, en revenant me voir, après un mois de mariage, me disaient qu'elles regrettaient de s'être mariées."

that is, out of 100 young women that the priest had in his care and who came to him regularly, 80 confessed to him after 1 month of being married(!) that they regretted it!