Year	per 1,000
1990	10.758554428466763
1991	10.683568942634592
1992	10.044701464236491
1993	9.77042850274566
1994	9.55912938277789
1995	9.324911654725263
1996	9.051053507340999
1997	8.747156086183901
1998	8.477089885163878
1999	8.220463960048795
2000	7.949327219093691
2001	7.729415122267618
2002	7.564459026445002
2003	7.474439175970319
2004	7.335468142388187
2005	7.3389586467382815
2006	7.057479145288383
2007	6.952119019883906
2008	6.7487225655447345
2009	6.529643865459006
2010	6.369804727462865
2011	6.120705367897108
2012	5.9136631641836095
2013	5.7062681535957465
2014	5.542330069541593
2015	5.373086532550921
2016	5.160018946470091
2017	4.994302412457578
2018	4.728220077408582
2019	4.488433254931902
2020	4.256625890858691
2021	4.018650265694255
2022	3.8781726483705445