Year	per 1,000
1990	9.636242236947671
1991	9.359535608853902
1992	9.142556522976916
1993	8.923808165956766
1994	8.712063541152471
1995	8.541469154978007
1996	8.344271355311353
1997	8.187169197334605
1998	8.023468287918085
1999	7.882367864231079
2000	7.734392438764643
2001	7.61327886925501
2002	7.543970150014008
2003	7.4147149206222105
2004	7.322491530613253
2005	7.2118697206692985
2006	7.0910367181121945
2007	6.945746502583154
2008	6.800528172407811
2009	6.843399551502753
2010	6.579299340235146
2011	6.471516550828253
2012	6.380977088473739
2013	6.291872287460433
2014	6.20076038584256
2015	6.158913692670698
2016	6.108625054561327
2017	6.070420357028131
2018	6.022976344441081
2019	6.0159672105608015
2020	5.950581161775717
2021	5.898725903751076
2022	5.791254723771819