pre-team age 5-6 - 3 hours a week
age 7 trained old 5 - 8 hours aweek
age 8 competed old 5 - 12 hours a week
age 9 competed old 5 then 3 meets old 6 - up to 16 hours/week
age 10 level 7 - 16 hours
age 11 repeat level 7 and now L8 - 16-20 hours now
No TOPS available, no higher hours available (not nec a problem...), repeated 7 by gymnast choice this year....no one "scores out" at her gym - but generally kids would only do one year at old 6 (or less like DD). Old 5/new 4 is the first level competed, so often repeated.
I'm sure you can see how much this varies - and there are also successful gymnasts who repeat many times (DD has moved "fast" for her gym...)