# year    value 
 1980    -0.33 
 1981     0.03 
 1982     1.29 
 1983    -0.05 
 1984     0.49 
 1985     -0.1 
 1986     0.51 
 1987     1.55 
 1988    -0.41 
 1989     -0.2 
 1990     0.49 
 1991     0.42 
 1992     0.43 
 1993    -0.64 
 1994     1.14 
 1995    -0.06 
 1996    -0.46 
 1997      0.5 
 1998    -0.58 
 1999     0.72 
 2000     1.55 
 2001     0.11 
 2002     0.82 
 2003     0.19 
 2004     1.04 
 2005     0.63 
 2006      2.3 
 2007    -0.72 
 2008     0.49 
 2009     1.36 
 2010     0.13 
 2011     1.29 
 2012     1.61 
 2013     1.19 
 2014     2.22 
 2015     0.97 
 2016     0.95 
 2017     0.32 
 2018     2.15