Table 2. Age-related incidence of acute hepatitis A in adult aged 20–59 years.

	Year
	2009	2010	2011		2012		2013
	NHIS	NHIS	KOSIS	NHIS	KOSIS	NHIS	KOSIS	NHIS
Case number
20–29 yrs	20,632	12,737	1,753	7,637	327	3,236	253	2,171
30–39 yrs	25,944	17,642	2,443	10,545	519	4,423	358	3,116
40–49 yrs	9,000	7,615	767	5,098	185	2,809	120	1,955
50–59 yrs	3,075	3,344	102	2,170	28	1,551	37	1,103
Total	58,651	41,338	5,065	25,450	1,059	12,019	768	8,345
Incidence by age (/100,000)
20–29 yrs	291.3	184.8	26.6	112.8	5.0	48.4	3.8	32.6
30–39 yrs	308.5	211.4	31.3	127.6	6.7	54.0	4.6	38.6
40–49 yrs	105.1	90.0	9.3	59.2	2.3	32.5	1.5	22.3
50–59 yrs	48.3	49.2	1.6	29.8	0.4	20.5	0.6	14.1
Total incidence (/100,000)	192.8	135.1		82.3		38.7		26.7

Abbreviation: NHIS, National Health Insurance Service; KOSIS, Korean Statistical Information Service.