Year	per 1,000
1990	4.354136113421658
1991	4.4048977721378835
1992	4.2648028725952125
1993	4.164742803758943
1994	4.029287615661291
1995	3.9029527058794864
1996	3.7981301763736317
1997	3.7069359541542393
1998	3.6240493867369863
1999	3.539642920975473
2000	3.434798519209491
2001	3.331561827166907
2002	3.1971863135004863
2003	3.092506573014472
2004	2.962027807110664
2005	2.845952148900485
2006	2.7663150798136846
2007	2.6869775065367376
2008	2.64062989136744
2009	2.5454258401504
2010	2.4494187915182244
2011	2.335317076988845
2012	2.2182241148634914
2013	2.1197041799490255
2014	2.021981486688828
2015	1.97849933403228
2016	1.9339089845817268
2017	1.878944410803054
2018	1.8454847260113394
2019	1.851388676216938
2020	1.8298134226549934
2021	1.8468133619117537
2022	1.9041381551302206