Table 1.

Descriptive Statistics for Memory and Functional Limitations over Chronological Age

	Memory			Functional limitations
Age	Number of Observations	M	SD	Number of Observations	M	SD
70	675	55.05	9.82	677	47.35	8.43
71	823	53.85	9.52	836	48.68	9.93
72	1144	53.79	9.74	1170	48.98	9.70
73	1185	53.31	9.54	1223	49.08	9.87
74	1397	53.37	9.32	1442	49.28	10.15
75	1478	52.77	9.52	1535	49.59	10.22
76	1553	52.12	9.20	1622	50.35	10.84
77	1626	51.77	9.48	1727	50.96	11.17
78	1678	51.08	9.06	1800	52.03	11.92
79	1654	50.14	9.09	1759	52.17	11.80
80	1711	50.04	9.05	1859	53.37	12.33
81	1678	49.52	8.82	1819	53.45	12.28
82	1614	49.20	8.68	1772	54.92	13.07
83	1515	48.06	8.57	1688	56.19	13.44
84	1413	47.86	8.73	1592	56.32	13.70
85	1191	47.06	8.37	1379	58.21	14.13
86	1024	46.82	8.52	1232	59.26	14.57
87	857	45.97	8.13	1045	61.00	14.93
88	710	45.65	8.41	888	61.44	14.69
89	575	44.90	7.96	735	63.19	14.81
90	506	44.06	8.12	623	63.46	14.17
91	348	45.02	8.52	475	65.94	15.24
92	291	43.05	7.58	389	65.78	14.91
93	205	44.12	8.13	287	67.66	14.88
94	146	42.64	6.97	222	68.89	15.13
95	100	41.87	7.30	174	71.71	14.94

Note. Memory and functional limitations were standardized to a T metric (M = 50, SD = 10) using the T1 AHEAD sample as the reference (N = 6,990).