Year	Percent
1991	5.006
1992	4.712
1993	4.786
1994	4.7
1995	4.584
1996	4.412
1997	4.211
1998	3.96
1999	3.52
2000	2.968
2001	2.971
2002	2.955
2003	2.991
2004	2.893
2005	2.827
2006	2.641
2007	2.645
2008	2.444
2009	2.455
2010	2.386
2011	2.334
2012	2.206
2013	2.164
2014	2.134
2015	2.047
2016	1.997
2017	1.998
2018	1.928
2019	1.862
2020	1.805
2021	1.749
2022	1.696