Table 3.

The evolution of asthma prevalence and the annual changes in prevalence

Study	Period	Sample	Lifetime asthma	Yearly change rate
Mitchell et al (19)	1968	952	7.1	0.46
	1982	858	13.5
Burr et al (10)	1973	818	5.5	0.43
	1988	965	12
Shaw et al (20)	1975	715	8	0.38
	1988	435	13.3
Mitchell et al (7)	1985	1084	14.2	0.35
	1991	1901	16.3
Peat et al (23)	1982	1487	11	2.08
	1992	1668	31.8
Omran et al (24)	1989	3403	10.2	1.88
	1994	4034	19.6
Downs et al (25)	1982	768	12.9	1.78
	1992	850	30.5
	1997	1016	38,6	1,62
Ng Man Kwoget (26)	1991	4543	17.9	1.22
	1999	4806	27.7
Selnes et al (22)	1985	10093	5.1	0.35
	1995	8676	8.6
Al Frayh AR (27)	1986	2123	8	1.6
	1995	1008	23