Year	Percent
1980	0.014
1981	0.015
1982	0.016
1983	0.016
1984	0.016
1985	0.016
1986	0.017
1987	0.018
1988	0.018
1989	0.019
1990	0.019
1991	0.02
1992	0.019
1993	0.019
1994	0.019
1995	0.02
1996	0.02
1997	0.02
1998	0.021
1999	0.021
2000	0.021
2001	0.022
2002	0.021
2003	0.022
2004	0.022
2005	0.021
2006	0.021
2007	0.021
2008	0.021
2009	0.022
2010	0.022
2011	0.022
2012	0.022
2013	0.022
2014	0.022
2015	0.022
2016	0.022
2017	0.022
2018	0.022
2019	0.022
2020	0.022
2021	0.022
2022	0.023
2023	0.023
2024	0.023