Year	Percent (Units)
1992	0.024
1993	0.021
1994	0.016
1995	0.014
1996	0.013
1997	0.012
1998	0.013
1999	0.013
2000	0.013
2001	0.014
2002	0.015
2003	0.016
2004	0.017
2005	0.017
2006	0.017
2007	0.018
2008	0.018
2009	0.019
2010	0.019
2011	0.020
2012	0.021
2013	0.023
2014	0.025
2015	0.023
2016	0.023
2017	0.024
2018	0.024
2019	0.026
2020	0.027
2021	0.028
2022	0.030
2023	0.031
2024	0.032
2025	0.032
2026	0.033
2027	0.033
2028	0.034
2029	0.034