Year	per 1,000
1990	7.844837462389294
1991	7.747555431551922
1992	7.555437864392117
1993	7.4840319290353
1994	7.37097923546535
1995	7.239326955228955
1996	7.067605224673098
1997	6.860079423555985
1998	6.68089276261345
1999	6.532245227239227
2000	6.336362826657682
2001	6.16781171181386
2002	6.0431796311539845
2003	5.952532377055671
2004	5.873359978036427
2005	5.677812052931711
2006	5.494018859329094
2007	5.427886120761771
2008	5.42427367462865
2009	5.26174151470044
2010	5.281345264774875
2011	5.103654651579194
2012	4.985947293591754
2013	4.894061309481408
2014	4.79521597271125
2015	4.714118887768026
2016	4.597990019285618
2017	4.509350312729998
2018	4.360601289867408
2019	4.241168229577688
2020	4.091550080132873
2021	3.973541336222997
2022	3.9136635552145527