Year Percent 1961 3.00917 1962 2.36827 1963 -7.33558 1964 2.5705 1965 -0.17238 1966 -1.02122 1967 -10.43027 1968 5.45558 1969 1.82323 1970 9.59989 1971 1.85549 1972 24.4393 1973 -12.10328 1974 -9.83393 1975 -8.61659 1976 9.20042 1977 12.06057 1978 8.68188 1979 2.38941 1980 1.51055 1981 3.71212 1982 3.63309 1983 1.39406 1984 5.80886 1985 5.43094 1986 4.87697 1987 -0.22395 1988 13.38893 1989 0.88614 1990 3.74206 1991 0.84588 1992 6.19095 1993 4.16519 1994 -1.28153 1995 7.77439 1996 1.33117 1997 3.57387 1998 4.16857 1999 2.75091 2000 1.62048 2001 1.62465 2002 6.16797 2003 7.48703 2004 3.95576 2005 2.31365 2006 7.52718 2007 -1.70793 2008 6.55171 2009 -2.17792 2010 -3.40834 2011 -0.44303 2012 1.3927 2013 1.83974 2014 0.95002 2015 1.73129 2016 1.09656 2017 1.36154