Year	per 1,000
1990	24.012070094696952
1991	23.357794922820958
1992	22.965807635295715
1993	22.54559975669029
1994	21.673966519673098
1995	21.105941993723015
1996	20.53926725749823
1997	20.00839993893891
1998	19.496399464294043
1999	18.840294029004898
2000	18.251098304610856
2001	17.69725257260134
2002	17.086371815612402
2003	16.508215031774643
2004	15.94150479653054
2005	15.402848240753753
2006	14.901360067115293
2007	14.446821476317803
2008	14.061105644172367
2009	13.557054619720493
2010	13.195324546102976
2011	12.801841384484327
2012	12.367018039694463
2013	12.022751776288759
2014	11.704581867354992
2015	11.408197024459655
2016	11.131362116785748
2017	10.861256921726728
2018	10.588798997493383
2019	10.35052535020357
2020	10.09603590842221
2021	9.835709736327777
2022	9.595186868525497