Until the very recent change, FIDE = ECF x 7.5 + 700
There was no mechanism for getting a grade of <700 which is effectively zero ECF. The ECF database is readily available for download which is necessary for all team captains. The provisional grade of a new registrant was 1400 (recently changed to ungraded until the average of the first 10 results could be used).
I think the average rating in England must be higher than in the USA. Probably more serious players across the pond and more scholastic players here.
Aside from a very small minority, UK chess clubs don't accept members less than age 16 or 18, mostly due to modern Vulnerability legislation, they would have to be escorted by a guardian which makes it impractical for away matches, and couldn't even got to the washroom on their own.
To 'lecture' or help at a junior chess club requires all sorts of background checks with certificates that have to be paid for so most (including myself), can't be bothered.
This means that almost all players below school leaving age are not included in the rating system.
How is cigar smoke loud?
He didn't say that. Reading comprehension...