1979      3.73
1980    -17.85
1981    -15.06
1982     11.39
1983      0.25
1984     -8.80
1985     -7.41
1986     -5.32
1987      2.57
1988      0.95
1989     -2.76
1990      1.18
1991      0.49
1992     -5.55
1993     -3.00
1994     17.66
1995     15.34
1996      6.98
1997    -10.65
1998      7.91
1999      5.13
2000      2.81
2001     17.66
2002     -8.57
2003     11.62
2004     11.62
2005      3.73
2006    -20.17
2007     -5.08
2008     33.21
2009     15.11
2010     -6.48
2011    -16.22
2012     16.03