Year	Percent
1980	0.001
1981	0.002
1982	0.002
1983	0.002
1984	0.002
1985	0.002
1986	0.002
1987	0.002
1988	0.003
1989	0.003
1990	0.003
1991	0.003
1992	0.003
1993	0.003
1994	0.003
1995	0.003
1996	0.003
1997	0.003
1998	0.003
1999	0.003
2000	0.003
2001	0.003
2002	0.003
2003	0.004
2004	0.004
2005	0.004
2006	0.004
2007	0.004
2008	0.004
2009	0.004
2010	0.005
2011	0.005
2012	0.005
2013	0.005
2014	0.005
2015	0.005
2016	0.005
2017	0.006
2018	0.006
2019	0.006
2020	0.006
2021	0.006
2022	0.006
2023	0.007
2024	0.007