Year	per 1,000
1990	6.984132872925952
1991	6.787898015582241
1992	6.682793685566764
1993	6.622739853678513
1994	6.5134511319887
1995	6.409503523138319
1996	6.2317997810892845
1997	6.073249199800669
1998	5.946216240469829
1999	5.8868559726244944
2000	5.739904185637287
2001	5.599933484080473
2002	5.491221431171333
2003	5.415314000659915
2004	5.31444349007912
2005	5.062136828807544
2006	4.92068252571874
2007	4.843585389951706
2008	4.763151901946091
2009	4.664834438251243
2010	4.6112015948439
2011	4.5115799985658205
2012	4.384512578869566
2013	4.280444335253588
2014	4.151813605655133
2015	4.037700036982459
2016	3.9003691441949404
2017	3.80826340812413
2018	3.6463625900927954
2019	3.546005895809286
2020	3.41892154690018
2021	3.3275659236457145
2022	3.307333596761729