Year	per 1,000
1990	1.2067803522406366
1991	1.1839268981327682
1992	1.1545718880429636
1993	1.1060615896594053
1994	1.0900930229568382
1995	1.077016282641055
1996	1.0116450672040307
1997	1.0070452290080913
1998	1.008503206135507
1999	0.9842765466100288
2000	0.9589826324384033
2001	0.9194623819373356
2002	0.8536280749073016
2003	0.7894850060872279
2004	0.7555944498705001
2005	0.7307062989029725
2006	0.6717783442771869
2007	0.6630529480504401
2008	0.6399458603543915
2009	0.6226702948590793
2010	0.5968755415380658
2011	0.569048377758706
2012	0.559514221887928
2013	0.535044443441294
2014	0.5287237274407525
2015	0.5038389781932998
2016	0.4859080088397791
2017	0.4816475759467378
2018	0.47229283278308987
2019	0.4642268168761808
2020	0.460468719279452
2021	0.45769581575743906
2022	0.45300603956838514