Table 3.

Mean Annual Incidence of Total Respiratory Illness per Person-Year (Tecumseh, Michigan, 1966–1971^∗)

Age Group (yr)	Mean Annual Illness Incidence
	Person-Years (n = 4,905)	Males	Females	Both Sexes
<1	121	6.3	6.0	6.1
1–2	302	6.0	5.4	5.7
3–4	284	4.4	5.1	4.7
5–9	844	3.4	3.7	3.5
10–14	720	2.4	3.1	2.7
15–19	318	2.1	2.8	2.4
20–24	234	2.2	3.3	2.8
25–29	397	2.4	3.1	2.7
30–39	897	1.9	2.7	2.3
40–49	502	1.4	1.9	1.7
50–59	125	1.3	1.8	1.6
≥60	161	0.9	1.4	1.3

^∗Adapted from JAMA.7