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