Year	per 1,000
1990	6.937017547122074
1991	5.97669749816594
1992	5.705852746562683
1993	5.499451567342713
1994	5.361647937839046
1995	5.2053488691213206
1996	5.034293037570936
1997	4.924364122957364
1998	4.762249196452299
1999	4.615000383320978
2000	4.516634264862376
2001	4.420721821737153
2002	4.381087958016889
2003	4.65570971355288
2004	4.21391578086905
2005	4.180851291868523
2006	4.140692597308057
2007	4.08864960029392
2008	4.101743195190805
2009	4.030258204514539
2010	4.012080776480701
2011	4.095350051647403
2012	4.66910263064564
2013	4.715583234627602
2014	4.525077278830174
2015	4.787235772606024
2016	4.549903678072981
2017	4.621452869627856
2018	4.73782325668265
2019	4.313224665288721
2020	4.034793098085044
2021	4.0029029376442065
2022	3.843502744704484