Year	Percent
1993	39.95
1994	39.95
1995	39.95
1996	39.95
1997	39.94
1998	39.94
1999	39.94
2000	39.94
2001	39.98
2002	40.03
2003	40.07
2004	40.12
2005	40.17
2006	40.2
2007	40.22
2008	40.25
2009	40.29
2010	40.32
2011	40.33
2012	40.33
2013	40.33
2014	40.34
2015	40.35