Year	per 1,000
1990	7.638486047801553
1991	7.701105324734017
1992	7.821478350182926
1993	7.942756586274026
1994	8.093159005069925
1995	8.28026773510915
1996	8.427128516544801
1997	8.581373666797173
1998	8.61211189564281
1999	8.584705804951865
2000	8.488737064246106
2001	8.37033344807195
2002	8.265903188652059
2003	8.171436100359413
2004	8.077626432618976
2005	8.002762925231792
2006	7.9424465170528675
2007	7.925945674254958
2008	7.914581761480809
2009	7.969375975757272
2010	8.026063816537834
2011	8.081210748397227
2012	8.142341418059987
2013	8.148079742472063
2014	8.038374068041213
2015	7.895836074100135
2016	7.675871373789047
2017	7.470897645191715
2018	7.207300633395094
2019	7.205460010203553
2020	6.7714754341695125
2021	6.584175415045853
2022	6.453758024433771