Year Percent 1971 -5.82003 1972 4.18938 1973 -0.86744 1974 2.83709 1975 6.52604 1976 4.1825 1977 -7.47661 1978 12.87626 1979 1.48357 1980 -16.83337 1981 16.18677 1982 1.92741 1983 -5.82376 1984 6.2772 1985 1.54516 1986 -3.17458 1987 0.50191 1988 2.20363 1989 3.65519 1990 3.60965 1991 2.57929 1992 -1.33951 1993 -0.31695 1994 0.88566 1995 2.23501 1996 9.4877 1997 4.63428 1998 -29.30966 1999 -0.70228 2000 3.52448 2001 0.23117 2002 -2.97623 2003 -1.53839 2004 0.54362 2005 1.96359 2006 0.00407 2007 0.88562 2008 0.77248 2009 0.8753 2010 2.02696 2011 5.3576 2012 -4.23176 2013 0.59353 2014 -1.62422 2015 3.44963 2016 3.61914 2017 3.3249