# year    value 
 1980     0.83 
 1981     0.87 
 1982     0.48 
 1983      1.1 
 1984      0.3 
 1985     0.55 
 1986     0.52 
 1987     0.45 
 1988     0.26 
 1989     0.02 
 1990     0.22 
 1991        1 
 1992     1.02 
 1993     0.59 
 1994     0.83 
 1995     0.54 
 1996     0.61 
 1997        1 
 1998     0.99 
 1999     0.05 
 2000     0.22 
 2001     0.38 
 2002     0.87 
 2003     0.67 
 2004     0.34 
 2005     0.47 
 2006     0.39 
 2007     0.21 
 2008      0.2 
 2009     1.19 
 2010     0.78 
 2011     0.42 
 2012     0.82 
 2013     0.66 
 2014     0.56 
 2015     1.38 
 2016     0.66 
 2017     0.93 
 2018     1.12