Year	per 1,000
1990	23.65920622580252
1991	22.90504814306743
1992	22.937899548884815
1993	23.276841094095666
1994	30.47662730811862
1995	22.859882463117568
1996	23.00786565082834
1997	22.420135983924897
1998	22.112860230863934
1999	22.176380026885152
2000	21.24393380577006
2001	20.77924634440321
2002	20.327547142452687
2003	19.845833604453585
2004	19.30490535251229
2005	18.749581156240584
2006	18.186270496829415
2007	17.619232874911212
2008	17.182225911264602
2009	16.465289043746495
2010	15.931922872262424
2011	15.41866049509005
2012	14.948844953410806
2013	14.510895851431343
2014	14.144613612049037
2015	13.805177512085658
2016	13.496295936819712
2017	13.217863976720293
2018	12.954810784445261
2019	12.768109728149554
2020	12.585169861694899
2021	12.44269492593135
2022	12.395163095347721