Year Percent 1961 4.68867 1962 5.84786 1963 5.44729 1964 6.2518 1965 7.90813 1966 4.86575 1967 8.22881 1968 9.3421 1969 3.04129 1970 13.61509 1971 7.08408 1972 8.18248 1973 11.16628 1974 -0.25817 1975 -7.91461 1976 3.90271 1977 4.48729 1978 1.71259 1979 4.51254 1980 3.46437 1981 0.7408 1982 1.51289 1983 -0.6352 1984 -2.25658 1985 2.52661 1986 4.04628 1987 6.41006 1988 7.6009 1989 6.59607 1990 4.17733 1991 4.60903 1992 1.1681 1993 -2.16302 1994 0.69352 1995 3.92237 1996 3.10827 1997 3.96103 1998 4.2635 1999 3.30225 2000 3.06057 2001 1.2269 2002 0.21843 2003 -1.30541 2004 1.56841 2005 0.58 2006 1.37009 2007 2.291 2008 0.0549 2009 -3.07055 2010 1.85192 2011 -1.68235 2012 -3.63838 2013 -0.58605 2014 1.43866 2015 2.24463 2016 1.94049 2017 2.99637