Table 1.

Unweighted descriptive statistics of samples from 29 states that participated in Youth Risk Behavior Survey (YRBS) in at least 3 years, 2001–2007

	2001	2003	2005	2007
Sample size (students)	53,292	60,114	76,342	82,296
Anthropometric variables
BMI percentile (mean)	60.3	61.1	62.5	62.6
Obesity (%)	10.6	11.4	11.9	12.5
Demographic variables (%)
Gender
Male	50.7	51.2	51.2	50.9
Female	49.3	48.8	48.8	49.1
Age
≤14	10.7	11.6	12.1	11.1
15	26.6	26.8	27.1	26.5
16	27.2	26.8	27.0	27.2
17	22.2	21.9	22.2	23.3
≥18	13.3	12.9	11.6	11.9
Race/ethnicity
Non-Hispanic White	67.3	63.9	62.2	61.1
Non-Hispanic Black	14.0	15.1	15.1	14.5
Hispanic	11.2	11.0	13.5	15.7
Non-Hispanic other	7.5	10.0	9.3	8.7
State participation
# of states that participated	19	26	28	28
Within-state sample size (students)
Median	2,120	1,781	2,375.5	2,398
Minimum	1,071	1,088	1,140	1,324
Maximum	7,067	9,320	9,708	13,439
Within-state student response ratea
Mean	81.2	82.2	78.8	78.1
Minimum	69	64	68	69
Maximum	90	94	92	89

^aStudent response rate = (number of useable questionnaires/number of students sampled)