Year	per 1,000
1990	5.62940573532881
1991	5.4952087955968
1992	5.3569463768158165
1993	5.2890464872417695
1994	5.163048874386447
1995	5.085700874342439
1996	4.915788523578067
1997	4.716558166132801
1998	4.524872040293577
1999	4.405197943911675
2000	4.235381919663671
2001	4.0646965823807415
2002	3.9669346449720777
2003	3.8056503188621638
2004	3.90458571801542
2005	3.495028862447819
2006	3.317637418641387
2007	3.246765189211212
2008	3.3813043912154104
2009	3.133608852893798
2010	3.0941317693014354
2011	3.045275284156322
2012	2.965498798182638
2013	2.948181658953165
2014	2.874650491389501
2015	2.843312062168565
2016	2.7642740484387875
2017	2.743145833648574
2018	2.6519497099154745
2019	2.616824962621235
2020	2.5064434573291456
2021	2.4956671575308826
2022	2.4662902371357394