Year	Percent
1991	6.018
1992	5.874
1993	5.83
1994	5.811
1995	5.799
1996	5.939
1997	6.095
1998	6.288
1999	6.44
2000	5.281
2001	4.949
2002	4.451
2003	5.083
2004	5.021
2005	5.01
2006	4.293
2007	3.826
2008	3.402
2009	2.865
2010	3.35
2011	3.848
2012	3.779
2013	4.166
2014	3.838
2015	3.621
2016	4.536
2017	4.523
2018	4.492
2019	4.42
2020	4.339
2021	4.291
2022	4.256