Year % net 1973 22.46957 1974 23.04631 1976 29.70386 1977 31.62607 1978 32.31564 1993 69.27544 1994 76.77567 1995 75.2558 1999 80.64397 2000 81.65938 2001 79.30832 2002 79.09426 2003 80.35618 2005 82.05246 2006 82.64076 2013 92.51532 2014 92.78381 2015 93.58598 2016 93.94509 2017 94.66479