Year Percent 1961 1.62165 1962 7.14811 1963 6.29664 1964 -2.73319 1965 3.87946 1966 -3.19768 1967 -2.69492 1968 -2.42642 1969 -8.11535 1970 0.20614 1971 2.77748 1972 -7.75683 1973 -19.31393 1974 5.78323 1975 -5.49587 1976 -2.15455 1977 4.70287 1978 10.23178 1979 4.08735 1980 -5.01415 1981 -2.2491 1982 -1.26613 1983 -7.45694 1984 -19.18247 1985 4.67614 1986 3.35881 1987 -2.75696 1988 3.83284 1989 -2.03786 1990 -4.2887 1991 -0.71869 1992 -9.53926 1993 -1.91206 1994 0.489 1995 -0.91901 1996 -0.18933 1997 -0.88073 1998 6.48417 1999 -4.12247 2000 -4.92783 2001 3.29215 2002 -0.66336 2003 1.54896 2004 -3.48507 2005 0.729 2006 1.95481 2007 -0.62447 2008 5.55645 2009 -4.38802 2010 4.33372 2011 -1.55196 2012 7.64245 2013 1.29943 2014 3.47543 2015 0.41125 2016 0.98702 2017 0.96605