You are correct the women above 40s are having more sex. (1) it's because they know what their sexual ticks are and (2) their hormones spike up around that age.

As for what a man can do to make his woman have more sex with him, I have written a lot of articles on how to please a woman. If you women is dissatisfied with sex, that can complicate your situation. So take a look at some of these articles I recommend. I hope they help.

https://medium.com/enjoyable-sex/3-tips-to-give-her-the-best-sex-shes-ever-had-df0674eccb9e

https://medium.com/heart-affairs/how-to-give-cunnilingus-like-a-pro-even-if-she-hates-oral-sex-96e745f4f2d5

https://medium.com/heart-affairs/how-to-add-some-sizzle-between-the-sheets-4965fdc027a2