Table 1– Numbers of subjects by age group with data on forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and FEV₁/FVC

Age range yrs	Study group
	Cauc	HK	IN	IR	MX	OM	TN	US2	US3	Total
Males
4–6	166	2	272	44	1	10	3	0	0	498
7–8	1075	30	397	166	253	46	121	44	44	2176
9–10	1325	63	298	95	695	92	123	125	102	2918
11–12	1009	81	295	94	308	62	102	115	119	2185
13–14	533	103	293	84	323	45	38	86	96	1601
15–16	529	79	0	139	218	78	1	131	125	1300
17–18	252	34	0	109	170	57	0	69	48	739
19–20	57	0	0	45	83	5	0	17	32	239
Total	4946	392	1555	776	2051	395	388	587	566	11656
Females
4–6	117	0	185	38	0	10	6	0	0	356
7–8	1110	50	262	74	288	54	104	43	51	2036
9–10	1435	72	206	64	594	60	133	123	86	2773
11–12	957	69	201	59	276	49	78	126	114	1929
13–14	423	105	141	75	295	92	45	113	112	1401
15–16	426	93	0	111	241	120	7	151	135	1284
17–18	177	68	0	86	178	83	0	79	61	732
19–20	64	4	0	33	60	6	0	39	27	233
Total	4709	461	995	540	1932	474	373	674	586	10744

Cauc: Caucasian (comprising Australia, England 8, 24, Germany and Austria 25, the Netherlands 21, 22 and US Caucasians (US1) 23); HK: Hong Kong 29; IN: India 27; IR: Iran 7; MX: Mexico 6; OM: Oman 26; TN: Tunisia 28; US2: African-Americans 23; US3: Mexican-Americans 23. Breakdown by age for Caucasians is available in the online supplementary material.