Year	per 1,000
1990	6.493723100708411
1991	5.295415912556653
1992	5.002034218852414
1993	4.747764116278032
1994	4.544498286342688
1995	4.363753727970101
1996	4.186740901303764
1997	3.997426779249079
1998	3.858421581937096
1999	3.6979970026694193
2000	3.5684467264825717
2001	3.4180058202558725
2002	3.302234076090471
2003	3.5744247546968664
2004	3.1142846771662382
2005	3.0601650073266664
2006	3.018959217619144
2007	2.9900524761156597
2008	2.9490197373939093
2009	2.9444430554494194
2010	2.8918182296273502
2011	2.942678309344057
2012	3.4099875701471136
2013	3.4218069389332944
2014	3.258547887549161
2015	3.181507875784379
2016	2.8360847024733
2017	2.805025409545705
2018	2.8003405840206343
2019	2.431167321832745
2020	2.2253779607340367
2021	2.2078269788197824
2022	2.051041696590006