Year % 1985 56.31695 1986 56.60107 1987 58.45018 1988 58.03687 1989 56.28829 1990 59.43472 1991 63.69764 2003 99.07959 2004 99.5175 2005 99.54004 2006 100 2007 99.31557 2008 97.84895 2010 97.87168 2011 99.23771 2012 91.66523 2014 99.69122 2015 99.77986