Table 2.

Annual Frequency of Respiratory Illness by Age: Cleveland Family Study, 1948–1957 ^∗

Age (yr)	Common Respiratory Disease
<1	6.72
1–4†	7.95
5–9†	6.21
10–14†	5.02
15–19†	4.71
20–24	4.09
25–29	4.82
30–34	4.45
35–39	3.83
40–44	3.68
45–49	3.97

^∗Adapted from Am J Hyg6 and Epidemiol Rev.2

^†Unweighted means of individual ages.