Year	per 1,000
1990	4.570035811666736
1991	4.53782677667083
1992	4.783635943770154
1993	4.688346783636613
1994	4.4474790597691625
1995	4.309408787959346
1996	4.15713793247608
1997	4.054036647980762
1998	3.9816739496303604
1999	3.9253516870302967
2000	3.8733290227910273
2001	3.8246431944612285
2002	3.746411203206235
2003	3.707304176838833
2004	3.6664794171277775
2005	3.6065149506401917
2006	3.5753335075186143
2007	3.5052188686120447
2008	3.407353097122259
2009	3.2518074109905144
2010	3.1028482001050643
2011	3.0262571281912223
2012	2.915609100702244
2013	2.8691046323072826
2014	2.8753436717902114
2015	2.836028530376695
2016	2.8458240503694676
2017	2.842163658983427
2018	2.8551047020289286
2019	2.915873107100075
2020	3.0261479690989694
2021	3.2264875484043696
2022	3.7116953266760313