Year	per 1,000
1990	15.939062647155309
1991	15.389292992462074
1992	15.222628254620188
1993	15.287640751612027
1994	14.806136242070165
1995	14.555430524245129
1996	14.411796127071996
1997	13.881509255021623
1998	13.56723358571313
1999	13.425074698392956
2000	12.924920961902112
2001	12.62070657446158
2002	12.318891815911718
2003	12.032839381974032
2004	11.755578529496766
2005	11.495933669660083
2006	11.282203000143975
2007	11.042280537880178
2008	11.365553317902744
2009	10.666275144381046
2010	10.938434559720173
2011	10.450104573997306
2012	10.583747749725005
2013	10.548478005072244
2014	10.397306549536216
2015	10.370000163023066
2016	10.120901605462999
2017	9.987313405590706
2018	9.83378507566302
2019	9.471944621705289
2020	9.181618858964216
2021	8.998595815031496
2022	8.934730045003615