Year	per 1,000
1990	5.227801954583955
1991	5.1071116937425325
1992	5.026204295923785
1993	5.037955404263645
1994	4.9598514365612125
1995	4.913369278516203
1996	4.691441191085171
1997	4.517616608196104
1998	4.343803468331904
1999	4.262984303687901
2000	4.115234081017293
2001	3.957199231963039
2002	3.847474784920329
2003	3.670371061904662
2004	3.524039536606189
2005	3.3618020385253344
2006	3.1900530769137636
2007	3.1039970654480378
2008	3.0462655346227554
2009	2.9878159990012216
2010	2.9304972894860613
2011	2.8796625773063447
2012	2.819176411142091
2013	2.8207429712765903
2014	2.7658279425590173
2015	2.755532446214661
2016	2.675417267153288
2017	2.629897532911129
2018	2.500794706102267
2019	2.436264653394017
2020	2.337881443206504
2021	2.2783998231049463
2022	2.254044255329257