Group A (n = 20)

Group B (n = 40)

Group C (n = 30)

Upper zone

6.3 ± 1.2 mA^a

2.6 ± 0.6 mA^b

2.3 ± 0.5 mA^c

(4.6 - 8.3)

(1.5 - 3.8)

(1.6 - 3.1)

Middle zone

5.0 ± 0.5 mA^d

2.3 ± 0.5 mA^e

2.1 ± 0.4 mA^f

(4.2 - 5.8)

(1.4 - 3.0)

(1.4 - 2.8)

Lower zone

4.8 ± 0.5 mA^g

2.5 ± 0.6 mA^h

2.2 ± 0.5 mAⁱ

(4.1 - 6.0)

(1.6 - 3.8)

(1.6 - 2.8)