Year	%
1986	100
1987	100
1988	100
1989	100
1990	100
1991	100
1992	100
1993	100
1997	99.94607
1998	100
1999	100
2000	99.67103
2001	99.97372
2002	99.67994
2003	100
2004	99.94577
2005	100
2006	100
2007	99.96187
2008	100
2009	100
2010	99.93703
2011	99.73408
2012	100
2013	99.84194
2014	100
2015	100
2016	99.79078