NBA: check your team's PER differential by position

http://www.82games.com/0809/BYPOSIT.HTM

For example (NBA Ranking in Parentheses):
LAL:
PG: -5.5......(28)
SG: +13.4...(2)
SF: +3.9......(7)
PF: +6.3......(2)
C: +10.0.....(3)

HOU
PG: -1.8......(17)
SG: +2.1...(7)
SF: +2.4......(10)
PF: +1.1......(10)
C: -3.9.....(21)

The Lakers starting PG sucks, which is well known. But how come Yao Ming is at 21?