Year Percent 1961 5.30238 1962 5.00157 1963 5.0991 1964 5.24089 1965 5.41421 1966 4.36823 1967 5.11462 1968 4.30845 1969 5.25202 1970 -8.4943 1971 -1.00909 1972 -5.65488 1973 5.40481 1974 -18.37823 1975 -16.50948 1976 2.99317 1977 6.82409 1978 11.6853 1979 23.37262 1980 4.15519 1981 -11.22186 1982 4.33556 1983 1.33729 1984 11.7747 1985 2.74231 1986 -0.09479 1987 1.18118 1988 0.57988 1989 4.91781 1990 -3.31874 1991 -5.93584 1992 -5.63897 1993 -1.55323 1994 1.38051 1995 2.79342 1996 2.88672 1997 0.93126 1998 3.60094 1999 5.86235 2000 2.63957 2001 0.85 2002 0.704 2003 -3.32513 2004 -1.23787 2005 1.28411 2006 0.50791 2007 -0.47909 2008 -4.10226 2009 -5.8441 2010 -0.14288 2011 -0.96148 2012 1.57075 2013 -1.78347 2014 -1.43582 2015 -0.17462 2016 -2.79369 2017 0.37782