1979 5.83 1980 -4.94 1981 -0.06 1982 0.45 1983 -4.15 1984 0.09 1985 0.45 1986 -4.44 1987 -4.44 1988 -2.35 1989 1.74 1990 -1.28 1991 -2.93 1992 -4.22 1993 -2.28 1994 1.45 1995 -0.63 1996 3.25 1997 -1.85 1998 0.37 1999 2.10 2000 3.46 2001 -0.13 2002 -7.09 2003 3.96 2004 3.10 2005 0.09 2006 0.37 2007 -0.42 2008 4.25 2009 3.46 2010 7.70 2011 -1.06 2012 1.95 2013 5.18