Year % of total 1990 93.92556938301948 1991 93.78245010781083 1992 91.17220052017481 1993 89.58488973713739 1994 67.3949278846489 1995 67.98200761885384 1996 72.99470786691971 1997 84.74508396498364 1998 85.61244938845093 1999 84.80497788829024 2000 87.89389885026793 2001 87.29585731475676 2002 87.74904709111728 2003 88.87669927476848 2004 89.00098520364685 2005 88.50970946891226 2006 90.49292977701133 2007 91.07144944482422 2008 92.31931424407594 2009 92.60429081282257 2010 91.65263533223984 2011 93.99664294654913 2012 91.94780332275738 2013 92.50400216671697 2014 77.5220449672342