Year	per 1,000
1990	3.321824670412108
1991	3.2966998325018673
1992	3.4004987561264657
1993	3.366980449347239
1994	3.2128118438273066
1995	3.2002988643847874
1996	3.1333598770318307
1997	3.0219709471903777
1998	2.9071801964331327
1999	3.0549055268841006
2000	2.7114632009815876
2001	2.625416584312125
2002	2.5343117790389043
2003	2.4347472956142098
2004	2.344153306761365
2005	2.227901777543531
2006	2.112039037831718
2007	1.9867226278905838
2008	1.866490647547393
2009	1.7389874568526422
2010	1.607240175311422
2011	1.5146898003666824
2012	1.414312263631681
2013	1.3261242370416237
2014	1.2627654832059159
2015	1.213481839792049
2016	1.1527882330736776
2017	1.1057983113407268
2018	1.0354510956210545
2019	0.9990591290726466
2020	0.9717213226729795
2021	0.9030357735501782
2022	0.9265419629551938