Year	per 1,000
1990	7.403749869438402
1991	7.036729356857329
1992	6.76490436911233
1993	6.460870616832833
1994	6.21278510033825
1995	5.953495239225309
1996	5.7126136140488155
1997	5.533962364965855
1998	5.3375191471439365
1999	5.197605625371785
2000	5.0495404802735555
2001	4.860337753400233
2002	4.713149541074683
2003	4.5861977440388495
2004	4.620939008110678
2005	4.20646911230556
2006	3.984942031536835
2007	3.79604592998379
2008	3.6640249593646335
2009	3.3979048810804686
2010	3.1933491879281695
2011	3.0055394268734434
2012	2.8254132253996054
2013	2.657950392444194
2014	2.4711420776583797
2015	2.290675808993512
2016	2.1290714215660285
2017	2.000412126483853
2018	1.8616521883642259
2019	1.7459158546181253
2020	1.6584911917092113
2021	1.569750193382377
2022	1.4665887807833131