Year % 1986 86.74282 1987 87.95995 1988 89.42824 1989 89.50516 1990 90.63437 1992 92.90178 1993 94.17928 2000 92.73008 2001 92.88215 2002 98.4986 2003 98.3064 2004 95.97476 2005 94.2212 2006 96.08703 2007 96.79583 2008 100 2009 96.68214 2010 97.75681 2011 97.24289 2016 96.93179