Year Percent 1976 2.27379 1977 4.40393 1978 -0.13215 1979 0.84225 1980 0.30705 1981 2.4115 1982 0.17741 1983 -0.34626 1984 -0.24007 1985 -1.30133 1986 -0.53387 1987 0.39794 1988 1.30239 1989 0.82952 1990 -0.54643 1991 -0.04179 1992 0.00965 1993 0.87646 1994 0.71801 1995 3.11461 1996 2.43281 1997 3.3163 1998 2.14979 1999 1.94303 2000 3.09851 2001 1.23073 2002 1.72038 2003 2.14428 2004 3.02144 2005 5.72797 2006 6.9476 2007 6.71809 2008 8.17173 2009 6.6516 2010 8.63699 2011 6.61958 2012 4.90808 2013 3.59679 2014 2.29324 2015 0.64513 2016 0.62273 2017 7.62806