That means that couples where husbands do no traditionally female tasks have sex the most: 4.85 times a month. Conversely, couples where men do all the female work have sex the least: 3.3 times a month
The report does reach some erroneous conclusions, though, like:
After all, a great sex life isn't everything.
Being a bit more serious, it also doesn't explain why the data would indicate this, it just has a warning from a female researcher to not try this at home.