Table 3: Mean and standard deviation of the cell density (number of cells per 10,000 μm2 area) in all four zones.

Zone 1Zone 2Zone 3Zone 4

16–20 yrs 3 . 6 6 ± 2 . 3 5 2 . 5 6 ± 1 . 8 8 2 . 8 2 ± 1 . 1 1 3 . 6 2 ± 1 . 6 5
21–30 yrs 6 . 9 7 ± 4 . 3 4 3 . 2 0 ± 1 . 6 5 2 . 8 3 ± 1 . 3 5 2 . 7 4 ± 1 . 2 3
31–40 yrs 3 . 7 9 ± 1 . 5 9 3 . 1 9 ± 2 . 2 4 2 . 2 9 ± 0 . 2 6 1 . 9 4 ± 0 . 1 5
41–50 yrs 5 . 9 9 ± 3 . 2 9 2 . 3 4 ± 0 . 7 0 3 . 1 4 ± 0 . 4 5 3 . 5 7 ± 1 . 4 5
51–60 yrs 9 . 0 3 ± 3 . 4 1 4 . 3 6 ± 2 . 2 2 4 . 2 8 ± 0 . 9 4 4 . 0 3 ± 0 . 5 6
61–70 yrs 9 . 2 9 ± 0 . 7 1 3 . 1 1 ± 0 . 5 0 3 . 7 6 ± 1 . 2 7 4 . 9 5 ± 1 . 2 3
71–80 yrs 3 . 0 5 ± 0 . 4 7 1 . 6 3 ± 0 . 4 5 2 . 0 0 ± 0 . 3 3 1 . 8 6 ± 0 . 3 5
81–90 yrs 4 . 5 6 ± 1 . 6 3 3 . 3 1 ± 1 . 3 4 3 . 1 3 ± 1 . 2 9 2 . 8 8 ± 1 . 3 2