Year Percent 1961 1.15707 1962 3.40287 1963 4.54619 1964 5.08351 1965 3.30595 1966 1.66434 1967 4.34755 1968 1.37504 1969 1.9009 1970 2.39365 1971 1.42202 1972 -1.14601 1973 1.70158 1974 3.24239 1975 -0.99239 1976 -0.37983 1977 -2.6026 1978 0.46321 1979 1.21909 1980 3.95718 1981 2.69511 1982 -2.91847 1983 -4.31857 1984 2.53453 1985 -3.51516 1986 -2.18685 1987 -0.04337 1988 2.05565 1989 0.24787 1990 -2.49304 1991 -3.27744 1992 -4.43038 1993 -1.12759 1994 0.93313 1995 0.98594 1996 2.33637 1997 0.86343 1998 -1.10255 1999 0.79824 2000 2.62955 2001 1.28103 2002 2.25436 2003 1.604 2004 3.25723 2005 4.04108 2006 4.43992 2007 4.25675 2008 2.11651 2009 -2.61734 2010 1.81363 2011 1.9426 2012 0.7964 2013 1.01906 2014 0.40505 2015 -0.0973 2016 -0.73489 2017 0.06657