Year	per 1,000
1990	6.11767081556641
1991	6.174804349349797
1992	5.781933117286555
1993	5.69232192499305
1994	6.163453257169485
1995	5.4266592365521
1996	5.329057455942748
1997	5.155137004921131
1998	5.048925436262509
1999	4.889089610790156
2000	4.697428951235292
2001	4.589174183100404
2002	4.4399009606140485
2003	4.404265809770383
2004	4.431520536178173
2005	4.256694069659488
2006	4.065942046991676
2007	3.9394156120984634
2008	3.971311929760382
2009	3.6980493506016083
2010	3.6828686336112164
2011	3.4119377487378055
2012	3.3312133064128018
2013	3.2083201915112602
2014	3.0563844051555082
2015	2.9841376662447106
2016	2.8244787431249065
2017	2.7510635244490333
2018	2.6491234908548087
2019	2.5416348629001506
2020	2.4731360707983883
2021	2.397084148026485
2022	2.290182402173996