Year	per 1,000
1990	3.225077335031879
1991	3.0466386770273735
1992	2.9266210324823154
1993	2.7839645129832995
1994	2.671857941722398
1995	2.571342159824122
1996	2.4891857191347517
1997	2.4200750266331794
1998	2.709196448517341
1999	2.251667164418634
2000	2.1737025084756763
2001	2.118421203004059
2002	2.0561301581262637
2003	1.9933491842754543
2004	1.968959203173392
2005	1.9116926873448343
2006	1.851903288770234
2007	1.825916463682205
2008	1.7314477571047027
2009	1.7096883368638665
2010	2.604112149799047
2011	1.6048795835857317
2012	1.5223937623068342
2013	1.5025633447540903
2014	1.4706358058379758
2015	1.392855720830808
2016	1.3748147667977757
2017	1.3504484880606928
2018	1.2925060528657297
2019	1.2777141415759894
2020	1.2651800418114165
2021	1.2673440475831073
2022	1.2303604965640353