Year	per 1,000
1990	6.928662027167588
1991	7.232680045137371
1992	6.619678518648133
1993	6.5095806292710465
1994	6.338147918439172
1995	6.21954759849173
1996	6.093202228977841
1997	5.859987247374122
1998	5.708857668703953
1999	5.5017964800746455
2000	5.277144218649235
2001	5.152060450754628
2002	4.9645314682992785
2003	4.880191565803728
2004	4.800634227874101
2005	4.838882882399096
2006	4.550029092146418
2007	4.407114119585749
2008	4.232235172714797
2009	4.153725700622554
2010	3.952180465706675
2011	3.7734330835646346
2012	3.6644164758690354
2013	3.492861757652714
2014	3.30771510589499
2015	3.243449224728145
2016	3.0526292521635567
2017	2.9683187134338076
2018	2.820728971529467
2019	2.732595143917453
2020	2.65976300441373
2021	2.576634293891882
2022	2.421374507928102