Year	Percent
1991	7.883
1992	7.464
1993	7.575
1994	7.282
1995	7.303
1996	7.324
1997	7.086
1998	6.615
1999	6.47
2000	6.02
2001	5.788
2002	5.724
2003	5.36
2004	5.249
2005	4.828
2006	4.813
2007	4.256
2008	3.895
2009	4.075
2010	3.931
2011	3.715
2012	3.48
2013	3.361
2014	3.356
2015	2.986
2016	3.09
2017	3.058
2018	3.02
2019	2.993
2020	2.96
2021	2.935
2022	2.913