Year Percent 1961 2.99006 1962 3.00482 1963 3.01392 1964 2.90618 1965 3.07887 1966 0.0416 1967 1.22775 1968 5.7938 1969 1.85392 1970 2.99085 1971 -0.94109 1972 2.51162 1973 13.22797 1974 26.69417 1975 4.31395 1976 18.22297 1977 28.75129 1978 4.4333 1979 6.5414 1980 24.14368 1981 2.97699 1982 8.30132 1983 9.04678 1984 17.9099 1985 0.34366 1986 -2.0204 1987 -4.07521 1988 -0.38093 1989 -1.01241 1990 -4.52327 1991 0.66349 1992 -0.02384 1993 6.15419 1994 46.38607 1995 11.04379 1996 4.98308 1997 6.20168 1998 3.63948 1999 0.78618 2000 2.24582 2001 7.39641 2002 6.66731 2003 4.80102 2004 -2.89062 2005 1.30131 2006 1.74402 2007 2.93314 2008 8.50257 2009 2.34574 2010 5.38642 2011 1.63542 2012 4.1174 2013 2.75171 2014 3.90936 2015 3.10615 2016 1.56835 2017 1.14316