at the time the national average was 10 hours a month. I have no idea what it is now. Less I would imagine.
It would be likely the national average is truly less than 10 hrs, IF that number was really the NA. The claimed NA has been 10 hrs in Canada for as long as I remember.
I tend to believe WT continually states 10 hrs since 10 is a reasonably attainable goal at only 2.5 hrs/week. If most publishers actually did 10/month, then I expect WT would raise the number to 12 then 15.
We had attended a study group where the conductor openly stated his goal (requirement) that every member of his group is to report the NA of 10 hrs/month. At the time, my SO and I may have been regularly reporting 5 or 6 each. Upon learning the conductor's requirement, we each immediately decided to reduce our time in FS.