Year	per 1,000
1990	1.0659496631058347
1991	1.061648330691117
1992	1.0280325011156943
1993	0.9804633335346843
1994	0.9696082366905489
1995	0.9600815202034759
1996	0.8891305412410359
1997	0.8626621784076156
1998	0.8396800745818553
1999	0.8095258886430738
2000	0.7697923848334217
2001	0.7344965310943872
2002	0.7022448878345584
2003	0.6702412276548803
2004	0.6602340388461201
2005	0.6502448225251585
2006	0.5860818169374064
2007	0.5806595741605763
2008	0.5671649718719742
2009	0.5490718220857976
2010	0.5236837429346536
2011	0.49952846770165005
2012	0.49579290694413414
2013	0.4676312983491462
2014	0.46306660504777886
2015	0.44950721496619345
2016	0.42967933955050525
2017	0.4241390266170139
2018	0.4195040585345726
2019	0.41312766078539476
2020	0.4137689030674944
2021	0.4102538280184881
2022	0.4090760119730157