Brooker Classes

High-Carbon

Low-Carbon

Undocumented

(n = 92)

(n = 16)

(n = 1)

• None/Brooker 0

52.2% (n = 48)

68.8% (n = 11)

0%

• Brooker I

31.5% (n = 29)

25.0% (n = 4)

0%

• Brooker II

10.9% (n = 10)

0%

0%

• Brooker III

5.4% (n = 5)

6.3% (n = 1)

100% (n = 1)

• Brooker IV

0%

0%

0%