Year	per 1,000
1990	5.111914680809711
1991	5.295947637566766
1992	5.0879863391902305
1993	5.016274994319224
1994	4.88123850788425
1995	4.700857033856348
1996	4.562011760447274
1997	4.373309676542938
1998	4.232569396936198
1999	4.104385737258006
2000	3.939275926057811
2001	3.8109060033305235
2002	3.710985342557549
2003	3.619796708325889
2004	3.537750862957636
2005	3.475046379250692
2006	3.447790910867556
2007	3.463845297781046
2008	3.5366997979151593
2009	3.4878857170567272
2010	3.4086723915383157
2011	3.286292929724421
2012	3.1431045144978214
2013	3.0018135750450186
2014	2.886898195877472
2015	2.7732266641890333
2016	2.6913894191607803
2017	2.643282483046521
2018	2.6124895116872864
2019	2.669257298500663
2020	2.6797938662558187
2021	2.721151342658895
2022	2.754055106612663