# year    value 
 1980    -0.74 
 1981     0.03 
 1982     1.05 
 1983     1.36 
 1984     -0.6 
 1985      0.2 
 1986     0.28 
 1987     0.19 
 1988     0.71 
 1989     0.35 
 1990     0.68 
 1991     0.91 
 1992     1.61 
 1993     0.73 
 1994     2.22 
 1995     0.91 
 1996      0.4 
 1997     0.72 
 1998     1.54 
 1999     1.16 
 2000     1.32 
 2001     1.24 
 2002      1.5 
 2003     4.06 
 2004        1 
 2005      0.9 
 2006     1.45 
 2007     1.52 
 2008     1.47 
 2009     1.65 
 2010     1.57 
 2011     1.24 
 2012     2.52 
 2013     1.83 
 2014     0.78 
 2015     2.99 
 2016     1.65 
 2017     2.91 
 2018     2.72