Results: males were more frequently involved than females (ratio 85.4: 14.6), the age groups 6 - 18 years: 14.6%, 19 - 60 years: 80.5% (p < 0.01).
Kết quả: Nam giới: 85,4%, tuổi 6-18: 14,6%, 19 - 60: 80,5%.