Year	per 1,000
1990	25.749836964478718
1991	25.08324146686312
1992	24.72431437076695
1993	24.37075900157933
1994	25.12581000772628
1995	22.83551487401447
1996	22.237586088481784
1997	21.614392058581767
1998	20.88619765652482
1999	20.181015648479868
2000	19.459452562364884
2001	18.788435237208457
2002	18.107899478197105
2003	17.459009363138208
2004	16.770040090405193
2005	16.102704780475836
2006	15.435757134632935
2007	14.80154386115054
2008	14.246468938045455
2009	13.609530750810817
2010	13.104524328210157
2011	12.595572498281026
2012	12.081431741283886
2013	11.6503000522641
2014	11.261022896954191
2015	10.911662339885357
2016	10.594355438144534
2017	10.29172775635082
2018	10.01163387905517
2019	9.759366668847225
2020	9.497165116861142
2021	9.235125352722159
2022	8.987014155042225