Year	per 1,000
1990	6.747374207282787
1991	6.72187576068931
1992	6.57547186390318
1993	6.44259271467261
1994	6.360769449725561
1995	6.372406460090291
1996	6.166378992037567
1997	6.091468244722986
1998	6.057709346982047
1999	5.984436101986548
2000	6.016943681215563
2001	5.8498303921603485
2002	5.762830990607603
2003	5.669097559452314
2004	5.609723057628074
2005	5.4269291948922165
2006	5.3293751281454815
2007	5.223810127035445
2008	5.096622955790458
2009	4.957584970356063
2010	4.82364722573108
2011	4.7099367234819765
2012	4.576922772077473
2013	4.445361402464283
2014	4.28445197345815
2015	4.134191688754092
2016	3.9966433894620956
2017	3.873629302279777
2018	3.7345268580380915
2019	3.6032910974365095
2020	3.5099565916059525
2021	3.3857658458451407
2022	3.298987928119155