Table 1.

Prevalence of lichen planus in Taiwan.

Year	Total			Male			Female			sex ratio
	N	No. of Lichen planus	P	N	No. of Lichen planus	P	N	No. of Lichen planus	P
1996	21,525,433	283	1.3	11,065,798	92	0.8	10,459,635	191	1.8	0.5
1997	21,742,815	357	1.6	11,163,764	113	1.0	10,579,051	244	2.3	0.5
1998	21,928,591	489	2.2	11,243,408	182	1.6	10,685,183	307	2.9	0.6
1999	22,092,387	880	4.0	11,312,728	344	3.0	10,779,659	533	4.9	0.6
2000	22,276,672	1195	5.4	11,392,050	455	4.0	10,884,622	739	6.8	0.6
2001	22,405,568	1417	6.3	11,441,651	520	4.5	10,963,917	894	8.2	0.6
2002	22,520,776	1461	6.5	11,485,409	544	4.7	11,035,367	915	8.3	0.6
2003	22,604,550	1249	5.5	11,515,062	465	4.0	11,089,488	782	7.1	0.6
2004	22,689,122	1433	6.3	11,541,585	553	4.8	11,147,537	879	7.9	0.6
2005	22,770,383	1495	6.6	11,562,440	530	4.6	11,207,943	965	8.6	0.5
2006	22,876,527	1560	6.8	11,591,707	529	4.6	11,284,820	1031	9.1	0.5
2007	22,958,360	1746	7.6	11,608,767	583	5.0	11,349,593	1163	10.2	0.5
2008	23,037,031	2058	8.9	11,626,351	660	5.7	11,410,680	1398	12.3	0.5
2009	23,119,772	2332	10.1	11,636,734	740	6.4	11,483,038	1592	13.9	0.5
2010	23,162,123	2475	10.7	11,635,225	750	6.4	11,526,898	1725	15.0	0.4
2011	23,224,912	2674	11.5	11,645,674	834	7.2	11,579,238	1840	15.9	0.5
2012	23,315,822	2871	12.3	11,673,319	834	7.1	11,642,503	2037	17.5	0.4
2013	23,373,517	2983	12.8	11,684,674	873	7.5	11,688,843	2110	18.1	0.4

P: prevalence rate per 100,000 population.