Table 1.

Sample characteristics (n = 11,617).

Variable	% (n)
Sex
Male	47.1% (5470)
Female	52.9% (6147)
Age (years)
18–24	11.3% (1314)
25–30	33.1% (3849)
31–39	11.8% (1365)
40–49	12.5% (1455)
50–59	17.9% (2083)
60–64	13.4% (1551)
Education level
Low	22.8% (2634)
Middle	27.7% (3202)
High	49.5% (5712)
Country
USA	33.2% (3855)
Canada	7.0% (815)
Australia	28.4% (3302)
UK	31.4% (3645)