Year	per 1,000
1990	3.930746669363663
1991	3.889383529284721
1992	3.8654601194472917
1993	3.780066308041262
1994	3.6949692436290373
1995	3.6089797789436155
1996	3.5171660437620353
1997	3.457572572404898
1998	3.341027873113192
1999	3.2539243402780653
2000	3.1927654113122212
2001	3.0748714268137642
2002	3.076433235097774
2003	2.9022182617621626
2004	2.8362842692570145
2005	2.7567414093769584
2006	2.6882664112459307
2007	2.748522311137914
2008	2.592554478698462
2009	2.77458705653981
2010	2.4729362500099326
2011	2.4286988472106787
2012	2.4082884064885497
2013	2.3313320036954943
2014	2.315624679514993
2015	2.3226409402546526
2016	2.372246542304665
2017	2.270962116518667
2018	2.293546575610933
2019	2.250203802834679
2020	2.335463713058633
2021	2.218882855925924
2022	2.2001171005482276