Year	Percent
1980	0.019
1981	0.018
1982	0.019
1983	0.02
1984	0.02
1985	0.02
1986	0.02
1987	0.02
1988	0.019
1989	0.019
1990	0.018
1991	0.017
1992	0.015
1993	0.015
1994	0.015
1995	0.015
1996	0.015
1997	0.015
1998	0.015
1999	0.016
2000	0.016
2001	0.016
2002	0.016
2003	0.015
2004	0.014
2005	0.014
2006	0.014
2007	0.013
2008	0.012
2009	0.012
2010	0.012
2011	0.011
2012	0.011
2013	0.011
2014	0.01
2015	0.01
2016	0.01
2017	0.009
2018	0.009
2019	0.009
2020	0.009
2021	0.009
2022	0.009
2023	0.009
2024	0.008