1979      2.82
1980     -1.70
1981      0.62
1982     -0.72
1983     -2.67
1984      2.46
1985     -1.70
1986     -3.35
1987     -0.35
1988     -0.35
1989     -1.39
1990     -2.00
1991     -0.96
1992      1.17
1993      0.20
1994      2.70
1995     -1.02
1996      1.30
1997      0.32
1998     -0.05
1999      2.40
2000      2.27
2001     -1.09
2002     -2.67
2003      3.01
2004      2.27
2005      1.72
2006      1.60
2007      0.81
2008      1.24
2009      1.79
2010      5.08
2011     -0.54
2012      2.21