Year % net 1971 11.89299 1980 17.89031 1983 14.47382 1984 14.85609 1985 12.05545 1986 13.53441 1987 15.61589 1989 16.15433 2000 31.59658 2001 33.29269 2002 35.27827 2004 38.86637 2005 40.65456 2006 41.69515 2010 44.6393