Year	Percent (Units)
1980	0.011
1981	0.011
1982	0.010
1983	0.010
1984	0.010
1985	0.010
1986	0.010
1987	0.010
1988	0.010
1989	0.010
1990	0.009
1991	0.008
1992	0.007
1993	0.007
1994	0.007
1995	0.007
1996	0.007
1997	0.007
1998	0.007
1999	0.007
2000	0.007
2001	0.006
2002	0.006
2003	0.006
2004	0.006
2005	0.006
2006	0.006
2007	0.006
2008	0.006
2009	0.005
2010	0.005
2011	0.005
2012	0.004
2013	0.004
2014	0.004
2015	0.004
2016	0.004
2017	0.004
2018	0.004
2019	0.003
2020	0.003
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