Year	Percent
1980	0.02
1981	0.02
1982	0.021
1983	0.02
1984	0.019
1985	0.019
1986	0.019
1987	0.018
1988	0.018
1989	0.017
1990	0.017
1991	0.018
1992	0.016
1993	0.017
1994	0.017
1995	0.017
1996	0.017
1997	0.018
1998	0.018
1999	0.018
2000	0.018
2001	0.019
2002	0.019
2003	0.019
2004	0.019
2005	0.018
2006	0.018
2007	0.018
2008	0.018
2009	0.019
2010	0.018
2011	0.018
2012	0.018
2013	0.019
2014	0.02
2015	0.019
2016	0.02
2017	0.02
2018	0.021
2019	0.021
2020	0.022
2021	0.022
2022	0.023
2023	0.024
2024	0.024