Year	per 1,000
1990	1.0795433113561375
1991	1.0387477057439616
1992	1.0020022531113055
1993	0.9682091971472356
1994	0.9319930493584386
1995	0.9057245129812596
1996	0.8495040954854192
1997	0.8184284383314493
1998	0.7588929470483753
1999	0.7437339831294025
2000	0.7157522019566341
2001	0.6740406058204823
2002	0.6614650633110225
2003	0.6100072943828
2004	0.5667236159791583
2005	0.5592024311047243
2006	0.5521670251789723
2007	0.5331987328110779
2008	0.5074124683295341
2009	0.45631827676761233
2010	0.4505350702924317
2011	0.4298968779959923
2012	0.4296480662574258
2013	0.4222877861318704
2014	0.41896070487162523
2015	0.4147647599772215
2016	0.40776598367655
2017	0.3890115207270523
2018	0.37346599171627015
2019	0.37185502601196957
2020	0.36982609838813263
2021	0.36317797464837365
2022	0.36165413827740844