Year	per 1,000 people
1991	2.762
1992	2.841
1993	2.937
1994	3.009
1995	3.075
1996	3.124
1997	3.139
1998	3.182
1999	3.217
2000	3.272
2001	3.327
2002	3.364
2003	3.401
2004	3.426
2005	3.448
2006	3.487
2007	3.533
2008	3.58
2009	3.648
2010	3.734
2011	3.822
2012	3.892
2013	3.984
2014	4.064
2015	4.12
2016	4.187
2017	4.251
2018	4.311
2019	4.391
2020	4.459
2021	4.518