Year	per 1,000
1990	4.907445534072996
1991	4.910426874145856
1992	4.65082289057286
1993	4.549059793572491
1994	4.4344320703825755
1995	4.364308280154392
1996	4.267590943418646
1997	4.125657649848027
1998	4.0319204593471625
1999	3.931918313793847
2000	3.7850272145610835
2001	3.70362244642763
2002	3.644335099663993
2003	3.6319839341726414
2004	3.689441395841734
2005	3.5962612488385473
2006	3.492715790326807
2007	3.4404593027081174
2008	3.5267901002346984
2009	3.318253995946583
2010	3.3033578606238843
2011	3.138300346248522
2012	3.0837525638932872
2013	2.991292786323073
2014	2.8980535818617743
2015	2.8551833892535585
2016	2.7652028922865486
2017	2.687292212992103
2018	2.6038411935636114
2019	2.5455989690092875
2020	2.4886657689705043
2021	2.4152184103551004
2022	2.3389927124329293