Year	per 1,000
1990	9.707904598669316
1991	9.495752184769895
1992	9.08653345106253
1993	8.891950033313165
1994	10.141410659918746
1995	8.520606848454298
1996	8.337141538925916
1997	8.115217706594953
1998	7.921316274037807
1999	7.751150522916416
2000	7.464735893427937
2001	7.278944184082991
2002	7.142679121334068
2003	7.085571005204725
2004	7.056923097400454
2005	6.861839517841743
2006	6.65097491713313
2007	6.540257162150031
2008	6.504196143673521
2009	6.206078166888551
2010	6.182209946188546
2011	5.878752954949296
2012	5.75745456181141
2013	5.573999937887377
2014	5.410952134805431
2015	5.287180996506107
2016	5.096104901687554
2017	4.971168705540216
2018	4.801572255712236
2019	4.577247763210453
2020	4.378982172501141
2021	4.226704318550918
2022	4.110069529670007