Year % net 1976 2.05251 1977 2.07995 1980 2.15232 1982 2.51639 1983 2.3506 1984 2.42699 1985 2.633 1986 2.84889 1987 3.14835 1993 5.05246 2009 13.09097 2010 15.17589 2011 16.88675 2012 18.42151 2013 21.40103 2014 25.95054 2015 28.89895 2016 32.18514 2017 28.30495 2018 27.52277