Year Percent 1961 1.5885 1962 -1.73185 1963 -14.57393 1964 8.69432 1965 8.16306 1966 3.22955 1967 2.56187 1968 -0.48801 1969 5.51821 1970 2.89646 1971 1.84865 1972 -4.42437 1973 0.1395 1974 6.54516 1975 7.32029 1976 0.42473 1977 -3.70152 1978 -2.7881 1979 -2.61076 1980 1.22545 1981 1.29116 1982 -13.13613 1983 -6.51741 1984 -4.5719 1985 3.03552 1986 -0.12591 1987 1.82553 1988 -2.82441 1989 -4.29861 1990 -2.73075 1991 5.84506 1992 7.27725 1993 7.44548 1994 7.8281 1995 4.57963 1996 7.80275 1997 6.41565 1998 -1.37684 1999 3.33444 2000 -1.1179 2001 2.39109 2002 1.10194 2003 -1.0017 2004 3.3221 2005 -1.86474 2006 5.31843 2007 7.2678 2008 2.18912 2009 3.63839 2010 4.01806 2011 4.83904 2012 4.7184 2013 4.30941 2014 3.12431 2015 2.47498 2016 2.6763 2017 2.32183