Year	per 1,000
1990	14.69038529812721
1991	14.486599058981252
1992	14.292553565689078
1993	14.056690431588082
1994	13.84135663623583
1995	13.555623835826221
1996	13.235479259869452
1997	12.992184637668682
1998	12.706936419178646
1999	12.41559545749357
2000	12.116715531833117
2001	11.856036019446776
2002	11.5958097414588
2003	11.328295052530043
2004	11.108299238691288
2005	11.67530042723996
2006	10.682439886838715
2007	10.536327906510888
2008	10.362662100394905
2009	10.212119843898188
2010	10.012859787533747
2011	9.814338542513548
2012	9.615068769470504
2013	9.43396777407911
2014	9.207793006003442
2015	9.005943645774142
2016	8.849373495287557
2017	8.65520406967924
2018	8.457540671305877
2019	8.253138197875252
2020	8.03759904407499
2021	7.818283744734374
2022	7.642741338432143