Year Percent 1961 -1.30788 1962 1.60364 1963 0.9223 1964 4.73079 1965 1.71311 1966 -3.20758 1967 1.60668 1968 -1.02198 1969 1.67209 1970 3.83286 1971 3.29361 1972 2.07924 1973 10.7933 1974 8.16108 1975 7.96756 1976 4.52493 1977 -1.07966 1978 2.94652 1979 1.05558 1980 1.05901 1981 2.94455 1982 -1.8996 1983 -2.80665 1984 0.09518 1985 1.38168 1986 0.93279 1987 -2.68566 1988 3.33489 1989 -1.40565 1990 1.23746 1991 1.86975 1992 -0.2195 1993 -0.31311 1994 1.9743 1995 0.07082 1996 -0.38322 1997 2.21494 1998 1.23843 1999 -6.54343 2000 -0.74859 2001 2.20154 2002 2.35038 2003 1.04138 2004 6.44847 2005 3.56202 2006 2.66754 2007 0.47815 2008 4.57482 2009 -1.1018 2010 1.83798 2011 6.14348 2012 3.98186 2013 3.32569 2014 2.21234 2015 -1.39697 2016 -3.02224 2017 1.51255