Year Percent 1971 2.94365 1972 3.80248 1973 4.44802 1974 0.85076 1975 -0.49643 1976 5.40021 1977 3.58144 1978 3.09818 1979 4.10433 1980 1.19869 1981 0.37624 1982 -0.30006 1983 1.83903 1984 3.17899 1985 2.55688 1986 2.24054 1987 1.2465 1988 3.30286 1989 3.09618 1990 4.35164 1991 4.34522 1992 1.15177 1993 -1.60514 1994 2.10261 1995 1.43907 1996 0.52648 1997 1.70029 1998 1.96418 1999 1.92124 2000 2.8227 2001 1.52454 2002 -0.16799 2003 -0.76486 2004 1.19194 2005 0.76391 2006 3.8172 2007 3.39871 2008 1.2747 2009 -5.37941 2010 4.2395 2011 5.59948 2012 0.30352 2013 0.21572 2014 1.50565 2015 0.86621 2016 1.12403 2017 1.79471