Year	per 1,000 uninfected population
1990	2.53
1991	2.45
1992	2.25
1993	2.05
1994	1.86
1995	1.76
1996	1.67
1997	1.57
1998	1.5
1999	1.41
2000	1.39
2001	1.3
2002	1.25
2003	1.16
2004	1.11
2005	1.05
2006	0.98
2007	0.9
2008	0.86
2009	0.84
2010	0.86
2011	0.83
2012	0.8
2013	0.8
2014	0.8
2015	0.81
2016	0.81
2017	0.78
2018	0.73
2019	0.7
2020	0.63
2021	0.58
2022	0.58