Year	per 1,000
1990	12.066844873984461
1991	12.100562751342023
1992	11.165878582160238
1993	10.78974176111006
1994	10.903011430880492
1995	10.002306728617
1996	9.600086284684771
1997	9.193683089107465
1998	8.772751167916388
1999	8.304888531684346
2000	7.877619799585659
2001	7.476593914180125
2002	7.155169295091565
2003	6.8912249205429035
2004	6.85324082318401
2005	6.42674536676064
2006	5.936848335531846
2007	5.636127819698867
2008	5.657952715506877
2009	5.00629896646328
2010	4.832674968011519
2011	4.3733451191748
2012	4.171278370923336
2013	3.9102431945401097
2014	3.6466523361956935
2015	3.399305084050065
2016	3.145686359973237
2017	2.962992810175065
2018	2.7922807128815643
2019	2.6008886166081755
2020	2.454554094593416
2021	2.3400614539951543
2022	2.2026987255584944