# year    value 
 1980     0.53 
 1981     0.86 
 1982     0.54 
 1983     0.02 
 1984    -0.83 
 1985     -0.3 
 1986      0.4 
 1987     1.43 
 1988     0.95 
 1989     0.76 
 1990     1.39 
 1991     0.89 
 1992     0.74 
 1993     1.25 
 1994     0.64 
 1995     0.84 
 1996     0.29 
 1997     1.11 
 1998     1.04 
 1999     2.34 
 2000     0.82 
 2001     1.35 
 2002     1.88 
 2003     1.07 
 2004      1.6 
 2005     0.52 
 2006      1.1 
 2007     1.86 
 2008    -0.47 
 2009     2.06 
 2010     1.24 
 2011     0.37 
 2012    -0.38 
 2013     0.84 
 2014     0.79 
 2015     1.63 
 2016     1.59 
 2017     2.37 
 2018     1.23