# year    value 
 1980    -0.06 
 1981     1.05 
 1982    -0.29 
 1983    -0.34 
 1984     0.45 
 1985     0.93 
 1986      1.7 
 1987     1.54 
 1988     0.88 
 1989     1.91 
 1990     1.41 
 1991    -0.38 
 1992     2.81 
 1993     1.33 
 1994     1.93 
 1995        0 
 1996     1.03 
 1997     1.36 
 1998    -0.01 
 1999     0.15 
 2000     2.07 
 2001     1.72 
 2002      0.6 
 2003     1.13 
 2004     2.43 
 2005     1.12 
 2006     1.25 
 2007      2.1 
 2008     0.01 
 2009     1.08 
 2010    -0.14 
 2011    -0.04 
 2012     2.03 
 2013      1.4 
 2014     1.64 
 2015     2.01 
 2016     2.02 
 2017     1.91 
 2018      1.9