Year	per 1,000
1990	5.350202059086924
1991	5.346855332418348
1992	5.110253994148474
1993	5.053604541073456
1994	5.219486942857057
1995	4.813120236120764
1996	4.71915305375557
1997	4.579237630754817
1998	4.487129554428045
1999	4.375548885459389
2000	4.230167977687304
2001	4.146670229592195
2002	4.085320413647182
2003	4.064897111456829
2004	4.105298537465562
2005	4.018620201791961
2006	3.9227715248652295
2007	3.867984924595246
2008	3.9344939101976673
2009	3.7411823181430144
2010	3.7185614819262858
2011	3.5661679842405487
2012	3.5138529626354846
2013	3.430248397487047
2014	3.336161080389513
2015	3.2917016730654556
2016	3.200771419278363
2017	3.134041412722698
2018	3.063257391246646
2019	2.9990280202194404
2020	2.9465790556254876
2021	2.8796539495935423
2022	2.808262617244176