Year	per 1,000
1990	7.104545842016648
1991	7.4064694823464325
1992	8.626270949388918
1993	9.162809945789151
1994	8.928771469725238
1995	9.28527144681894
1996	8.46128198798154
1997	8.342382423041757
1998	8.395760305852239
1999	8.642175919142534
2000	8.417392033221905
2001	8.248313712355898
2002	7.957985537903855
2003	7.569363115758249
2004	7.244263579847788
2005	7.02675904838142
2006	6.800780452790071
2007	6.521921914804111
2008	6.199352911619241
2009	5.7762247368939805
2010	5.504981276172087
2011	5.221224444370196
2012	4.949011675119111
2013	4.717554432591674
2014	4.519203379764261
2015	4.2030183109740475
2016	4.057926801769092
2017	3.731867821116592
2018	3.5651074636240163
2019	3.516309020839475
2020	3.6618915641793044
2021	3.547871131228932
2022	4.880803026414283