Year	per 1,000
1990	2.6826415498553495
1991	2.626399715088641
1992	2.4972685024776933
1993	2.4444127646296754
1994	2.3449861927028057
1995	2.2920602150403986
1996	2.2703452185981967
1997	2.1886980435155268
1998	2.3399858608333597
1999	2.147710669436797
2000	2.0745350403269613
2001	2.0674454190509945
2002	2.0399296657958743
2003	1.999581069854457
2004	2.0181815170550426
2005	1.9830714607828073
2006	1.9218360115203856
2007	1.9078093889437506
2008	1.8911820311948007
2009	1.8701637262908704
2010	2.55808943877673
2011	1.803474800016972
2012	1.7286440318776197
2013	1.716585494933438
2014	1.664289358604075
2015	1.653235154438491
2016	1.626923837070122
2017	1.5923626977923189
2018	1.5813477902206083
2019	1.5660728565692392
2020	1.5493190235805812
2021	1.5637954789896404
2022	1.5609529572570804