Year Percent 1961 6.25717 1962 5.5653 1963 -3.09475 1964 2.42781 1965 0.86444 1966 13.19287 1967 -3.00671 1968 1.22055 1969 2.70631 1970 51.27848 1971 1.34803 1972 2.89287 1973 5.34684 1974 43.94637 1975 23.50079 1976 14.35319 1977 10.71375 1978 13.91475 1979 11.48876 1980 12.41966 1981 18.45904 1982 4.82934 1983 13.76747 1984 13.26743 1985 5.54234 1986 11.63 1987 67.39822 1988 22.92167 1989 45.04047 1990 9.29085 1991 17.60477 1992 68.06319 1993 26.1324 1994 31.00914 1995 113.07639 1996 32.72709 1997 1.01313 1998 -5.66569 1999 17.05014 2000 35.22953 2001 -0.32262 2002 39.89666 2003 11.14094 2004 -0.15775 2005 22.0244 2006 17.33778 2007 4.77074 2008 10.8353 2009 -4.32057 2010 103.8228 2011 9.5101 2012 9.27124 2013 5.8733 2014 4.66262 2015 2.86367 2016 9.54367 2017 11.11654