Year % 1998 90.53997 1999 93.59169 2000 92.01975 2001 90.50348 2002 91.55488 2003 91.20814 2004 90.06002 2006 88.36898 2007 89.46578 2008 90.25329 2009 92.32814 2010 93.3876 2011 94.37356