Are all journalists innumerate? Article claims " most" couples have sex this often, then report a rate of 37%. That is not most. More had sex less often. The 3-4 times a week crowd was the biggest group, but that was largely a result of the way the sampling groups were broken down.
Also, the article implied having more sex made you happier, but I suspect it is more likely that happy couples were inclined to have sex more often. The dim-wittedness of journals never cease to amaze me, but then Rupert Murdoch loves these lascivious topics, also anything to make you feel inadequate, such as the constant Richest..... Lists.