Year % net 1980 58.99967 1983 65.15376 1984 63.4174 1985 64.44154 1991 74.81371 1998 80.02673 1999 79.93729 2002 80.41887 2004 87.5413 2005 86.77164 2006 85.25507 2010 91.7859