False.
There are no norms when it comes to sex, only averages, which are not at all the same thing. Don't forget that the figures either side of the average are also important!
The current average (true or otherwise) is just under three times a week. You may know some people who make love every day or more, while once a week may be enough for others.
No-one is normal or abnormal, everyone has their own needs and routines. The main thing is that both partners are satisfied with their sex life.
It is also very common for a couple to go through times of intense sexual activity, followed by quieter periods, which is prefectly natural in a long-term relationship.
They're only figures after all, and can only ever give a general idea of the quality of your sex life. Sometimes it's better to have a long, sensual session once a fortnight, than daily quickies, so find a rhythm and go with whatever works for you.