Year	per 1,000
1990	23.791244642042926
1991	23.184571624660308
1992	22.524137878684826
1993	22.153042486807596
1994	21.214842933738918
1995	20.58793720978911
1996	19.930146892676614
1997	19.339916744201926
1998	18.78834069208334
1999	18.088001551674033
2000	17.474828207249217
2001	16.88546786726541
2002	16.273636857757765
2003	15.66148786715155
2004	15.10432952847497
2005	14.499089607532062
2006	13.944283755425213
2007	13.421426678382737
2008	14.016911809196218
2009	12.3986206325173
2010	12.415215173394934
2011	11.544686414145339
2012	11.221775463777579
2013	10.852251501619756
2014	10.47401043321644
2015	10.161991854865999
2016	9.815961533521467
2017	9.58434858925679
2018	9.389018328933345
2019	9.086003156828037
2020	8.836660663918643
2021	8.65969426438628
2022	8.459911674952693