Year	Percent (Units)
1980	0.007
1981	0.008
1982	0.008
1983	0.007
1984	0.008
1985	0.008
1986	0.008
1987	0.008
1988	0.007
1989	0.007
1990	0.007
1991	0.007
1992	0.006
1993	0.006
1994	0.006
1995	0.006
1996	0.006
1997	0.006
1998	0.006
1999	0.006
2000	0.005
2001	0.005
2002	0.005
2003	0.005
2004	0.005
2005	0.005
2006	0.005
2007	0.005
2008	0.005
2009	0.005
2010	0.005
2011	0.005
2012	0.005
2013	0.003
2014	0.003
2015	0.003
2016	0.003
2017	0.003
2018	0.003
2019	0.003
2020	0.004
2021	0.003
2022	0.003
2023	0.003
2024	0.003
2025	0.003
2026	0.003
2027	0.003
2028	0.003
2029	0.003