There are many who say they are Catholics but I have no idea how many actually follow these rules.

https://www.guttmacher.org/article/2012/02/guttmacher-statistic-catholic-womens-contraceptive-use

In April 2011, the Guttmacher Institute published the results of an analysis finding that 99% of all women of reproductive age who have ever had sex—including 98% of such Catholic women—have used a method of contraception other than natural family planning.

By their early 20s, some 79% of never-married women—and 89% of never-married Catholic women—have had sex