Year Number of 1990 88.59 1991 92.17 1992 94.51 1993 95.56 1994 98.5 1995 104.39 1996 108.12 1997 114.78 1998 121.94 1999 122.48 2000 120.95 2001 111.63 2002 105.29 2003 98 2004 93.67 2005 91.78 2006 97.22 2007 103.18 2008 108.29 2009 112.86 2010 117.02 2011 120.34 2012 124.01 2013 129.17 2014 135.29 2015 143.09 2016 152.05