Year	per 1,000
1990	20.608313873785505
1991	19.317058426119686
1992	19.07548317139293
1993	18.84154387815074
1994	18.60142127790923
1995	18.475367781642024
1996	18.123506350362685
1997	17.82961243752564
1998	17.674177125001698
1999	17.380150336009862
2000	17.068382942155516
2001	16.773287756817922
2002	16.51550930075841
2003	16.264187196033593
2004	15.923219458788171
2005	15.597116967933173
2006	15.320311285528222
2007	15.03908716174259
2008	14.74869651850733
2009	14.437692761960179
2010	14.153485282139508
2011	13.881918993377344
2012	13.603958625313233
2013	13.282558307852993
2014	13.037332383415404
2015	12.814970784949947
2016	12.511705008084473
2017	12.31082587662168
2018	12.032504300619259
2019	11.881343184190458
2020	11.70554508608013
2021	11.597529828261715
2022	11.551053239023652