Table 1.

Descriptive Characteristics of the Samples in This Study

							Scaled scores
Test year	N	Age (years)	Birth year	Females (proportion)	Health	Education (years)	Vocabulary	Digit Symbol	Logical Memory	Word Recall
2001	205	50.7 (17.3)	1950 (17.3)	.65 (.5)	2.1 (0.9)	16.0 (2.5)	13.3 (3.2)	12.2 (2.8)	12.0 (3.1)	13.0 (2.9)
2002	269	48.3 (17.8)	1954 (17.8)	.63 (.5)	2.0 (0.8)	15.9 (2.8)	12.2 (3.1)	11.9 (3.1)	11.5 (2.7)	12.5 (3.0)
2003	330	47.4 (17.5)	1956 (17.5)	.66 (.5)	2.0 (0.8)	15.7 (2.6)	12.6 (3.0)	11.9 (2.9)	12.3 (2.8)	13.3 (3.4)
2004	458	51.3 (18.0)	1953 (18.0)	.63 (.5)	2.0 (0.9)	15.6 (2.6)	12.9 (2.9)	11.3 (2.8)	12.1 (2.6)	12.4 (3.4)
2005	670	49.8 (19.8)	1955 (19.8)	.66 (.5)	2.0 (0.8)	15.4 (2.8)	12.9 (3.3)	11.0 (2.9)	11.7 (3.0)	12.1 (3.2)
2006	913	51.1 (19.2)	1955 (19.2)	.66 (.5)	2.5 (0.9)	15.7 (2.5)	12.9 (2.7)	11.4 (2.7)	11.9 (2.8)	12.4 (3.2)
2007	444	52.3 (19.4)	1955 (19.4)	.62 (.5)	2.1 (0.9)	15.6 (2.8)	11.9 (2.8)	10.9 (2.9)	11.5 (3.0)	11.5 (3.5)
2008	255	54.6 (16.8)	1953 (16.8)	.64 (.5)	2.2 (0.9)	15.5 (2.9)	11.2 (3.2)	10.7 (3.0)	11.1 (3.0)	10.7 (3.4)
2009	236	57.1 (15.7)	1952 (15.7)	.69 (.5)	2.1 (0.8)	15.7 (2.6)	11.8 (3.1)	11.1 (2.7)	11.4 (3.0)	11.3 (3.4)
2011	440	52.5 (14.5)	1958 (14.6)	.68 (.5)	2.2 (0.8)	15.9 (3.0)	11.7 (3.6)	10.8 (2.8)	11.4 (3.4)	11.3 (2.9)

Note: The table presents mean values, with standard deviations in parentheses. Numbers in parentheses are standard deviations. Health was self-reported on a scale from 1, excellent, to 5, poor. The Vocabulary and Digit Symbol scaled scores are age-adjusted scores derived from the Wechsler Adult Intelligence Scale—Third Edition (Wechsler, 1997a), and the Logical Memory and Word Recall scaled scores are age-adjusted scores derived from the Wechsler Memory Scale—Third Edition (Wechsler, 1997b).