Age (year)

n (%)

CVI

Present

Absent

18 - 25

436 (13.9%)

0 (0.0%)

431 (98.9%)

26 - 40

815 (26.1%)

2 (0.2%)

800 (98.2%)

41 - 60

1154 (36.9%)

11 (1%)

1107 (95.9%)

61 - 80

723 (23.1%)

17 (2.4%)

688 (95.2%)

Total

3128 (100%)

30 (%1%)

3026 (96.7%)