Depth

Age range

Test control

5 - 20 years

20 - 35 years

35 - 50 years

50 years and over

10 cm

25.04 ± 1.47

24.49 ± 2.40

22.94 ± 0.89

26.93 ± 1.56

24.99 ± 1.75

20 cm

21.67 ± 1.27

18.42 ± 1.28^a

18.71 ± 0.97^α

20.82 ± 1.41

24.03 ± 0.65

30 cm

15.82 ± 0.25

16 .67 ± 0.66

14.56 ± 0.66

21.69 ± 0.99***

16.60 ± 0.33