Year Number of 1990 75.24 1991 78.16 1992 81.05 1993 83.84 1994 86.78 1995 90.03 1996 91.54 1997 93.18 1998 95.05 1999 97.13 2000 99.54 2001 94.39 2002 89.85 2003 86 2004 82.26 2005 78.59 2006 77.24 2007 75.7 2008 74.48 2009 73.49 2010 72.9 2011 74.74 2012 77.05 2013 79.65 2014 82.37 2015 85.1 2016 87.74