1979     -2.26
1980      2.91
1981      0.76
1982     -1.34
1983      0.45
1984      2.11
1985      1.07
1986     -4.29
1987     -2.57
1988      2.30
1989     -0.97
1990     -1.40
1991     -1.15
1992      0.14
1993      1.01
1994      1.07
1995     -1.64
1996      0.76
1997      0.08
1998      2.48
1999      0.51
2000     -0.04
2001     -2.94
2002     -2.01
2003      1.81
2004      2.05
2005      3.35
2006      3.22
2007      0.02
2008      2.18
2009      0.82
2010      4.33
2011     -0.53