Year	Percent
1980	0.016
1981	0.016
1982	0.015
1983	0.012
1984	0.011
1985	0.011
1986	0.01
1987	0.011
1988	0.012
1989	0.012
1990	0.012
1991	0.012
1992	0.01
1993	0.011
1994	0.011
1995	0.011
1996	0.014
1997	0.015
1998	0.016
1999	0.017
2000	0.016
2001	0.018
2002	0.019
2003	0.019
2004	0.02
2005	0.02
2006	0.021
2007	0.022
2008	0.023
2009	0.024
2010	0.024
2011	0.025
2012	0.026
2013	0.027
2014	0.028
2015	0.029
2016	0.029
2017	0.029
2018	0.029
2019	0.029
2020	0.029
2021	0.029
2022	0.03
2023	0.031
2024	0.034