Year	per 1,000
1990	20.537151308495826
1991	21.128306949970575
1992	19.49482650284177
1993	19.149870559418932
1994	19.420470641876307
1995	17.81730545771411
1996	17.226099160440636
1997	16.58404632098174
1998	15.994879103107658
1999	15.11601755160165
2000	14.462986941219372
2001	13.910079320970132
2002	13.382021270050394
2003	12.915946417042473
2004	12.588678791730825
2005	12.32686807926412
2006	11.64618346063325
2007	11.248499308655223
2008	11.4413788101787
2009	10.471809272610011
2010	10.322882282906098
2011	9.737425774824166
2012	9.47526748938832
2013	9.194171414620701
2014	8.916668351594467
2015	8.703566549156571
2016	8.435239917111796
2017	8.242395042930118
2018	8.077591561184652
2019	7.833811163135669
2020	7.634883185397626
2021	7.464925295137826
2022	7.277049406870766