Year	per 1,000
1990	2.7339366242896266
1991	2.6749291511174604
1992	2.541363957283498
1993	2.4857544119866266
1994	2.3838168489766676
1995	2.32780245763426
1996	2.3031328266845823
1997	2.214904839151747
1998	2.380459956652143
1999	2.1733613572942296
2000	2.095448505534258
2001	2.0867481505538796
2002	2.050027325125333
2003	2.0102092305919954
2004	2.0288167982805145
2005	1.9910061935871064
2006	1.923502291849328
2007	1.9138357500310799
2008	1.8979655531985467
2009	1.880120932638829
2010	2.6254353606271104
2011	1.807196298026665
2012	1.7301311045715713
2013	1.7168142022820805
2014	1.6613556811051358
2015	1.6533181582427858
2016	1.6249200237797492
2017	1.56957110247796
2018	1.5588013040806254
2019	1.5553886733653255
2020	1.537383494346848
2021	1.5534855023514946
2022	1.553093093378015