Based on the US offsite statistics (from the training excel), i'd say that it is less affected or negligibly so. My stats may obviously change a lot depending on skill level and various other factors but generally:
For a 7"6 player (inside freak that is), the difference in number of weeks per pop (holding levels constant) between age 18 and age 23 are:
JS = 6.03
JR = 8.84
OD = 8.03
HA = 5.10
DR = 4.02
PA = 3.44
IS = 3.68
ID = 3.68
RB = 3.68
SB = 3.36
For a 6"0 player (Spud Webster), the difference in number of weeks per pop (holding levels constant) between age 18 and age 23 are:
JS 5.00
JR 4.28
OD 4.73
HA 3.79
DR 4.65
PA 4.02
IS 6.80
ID 6.98
RB 6.31
SB 4.73