TABLE 1.

Retention rates across study cohorts and survey years

	Younger cohort	Middle cohort	Older cohort
2010–11 (age 21)	n = 809; 87%	n = 826; 84%	n = 788; 81%
2012–13 (age 23)	n = 787, 85%	n = 817, 83%	n = 795, 82%
2014–15 (age 25)	n = 828, 89%	n = 866, 88%%	n = 826, 86%