Year	Percent
1991	6.614
1992	6.385
1993	6.244
1994	6.6
1995	6.687
1996	6.547
1997	6.251
1998	5.909
1999	5.675
2000	5.798
2001	5.434
2002	5.5
2003	5.282
2004	4.933
2005	5.265
2006	5.211
2007	5.452
2008	5.269
2009	5.426
2010	5.403
2011	5.182
2012	5.053
2013	4.918
2014	5.075
2015	4.815
2016	4.72
2017	4.685
2018	4.613
2019	4.556
2020	4.498
2021	4.46
2022	4.423