Year	Percent
1980	0.001
1981	0.001
1982	0.001
1983	0.001
1984	0.001
1985	0.001
1986	0.001
1987	0.001
1988	0.001
1989	0.001
1990	0.001
1991	0.001
1992	0.001
1993	0.001
1994	0.001
1995	0.001
1996	0.002
1997	0.004
1998	0.005
1999	0.006
2000	0.012
2001	0.019
2002	0.022
2003	0.025
2004	0.031
2005	0.032
2006	0.032
2007	0.035
2008	0.04
2009	0.041
2010	0.035
2011	0.036
2012	0.038
2013	0.035
2014	0.034
2015	0.03
2016	0.026
2017	0.024
2018	0.022
2019	0.021
2020	0.019
2021	0.017
2022	0.016
2023	0.015
2024	0.014