Table 1 Mean FEV₁%/FVC and FEV₁ values from 28 authors and from the study of Albers and colleagues1

	FEV₁/FVC (%)			FEV1 (l)
Age (year)	43	48	Decline	43	48	Decline
Mean	80.2	79.2	1.0	3.486	3.350	0.135
Range	73.8–84.1	72.4–83.5	0.4–1.6	3.10–3.82	2.95–3.66	0.11–0.16
Mean1	84.5	79.3	5.2	3.532	3.335	0.197
SD1	9.8	8.8	–	0.833	0.806	–

FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity.