Table 1
Demographics of the study population
Characteristic
Total number of participants=18 825
Age: mean (SD)
19 (5) years
Sex: n (%)
Male
13 567 (72)
Female
5258 (28)
Race: n (%)
White
16 824 (89)
Black
1095 (6)
Other
906 (5)
Athletic status: n (%)
Athlete
8939 (47)
Non-athlete
9886 (53)