Year % net 1974 1.39895 1976 1.68804 1977 2.11378 1978 2.53561 1979 3.06804 1981 3.50079 1990 5.36037 1991 5.78795 1997 5.4615 1999 5.38559 2001 5.28282 2002 5.50642 2003 6.13784 2004 7.51201 2005 8.52719 2007 8.86268 2008 9.46457 2009 9.59377 2010 10.86772 2011 11.53509 2014 15.15304 2015 16.63379 2017 20.06691