Year Percent 1980 111.06647 1981 43.51 1982 39.436 1983 44.92857 1984 70.30957 1985 59.1437 1986 49.86667 1987 59.50833 1988 62.83145 1989 68.09385 1990 74.79866 1991 67.09433 1992 87.55088 1993 66.58408 1994 57.70292 1995 75.83155 1996 65.215 1997 67.16271 1998 58.97772 1999 71.40864 2000 64.80193 2001 71.77668 2002 73.67952 2003 60.35119 2004 60.42765 2005 69.87927 2006 62.99429 2007 61.39268 2008 59.42717 2009 56.16893 2010 50.22772 2011 56.6466 2012 60.82246 2013 55.45231 2014 65.63731 2015 81.41158 2016 70.45989 2017 62.962