# year    value 
 1980      0.4 
 1981     0.06 
 1982     0.21 
 1983     0.53 
 1984     0.37 
 1985     0.69 
 1986     0.21 
 1987      0.6 
 1988      0.4 
 1989     0.55 
 1990      0.3 
 1991     0.33 
 1992        0 
 1993     0.39 
 1994     0.32 
 1995     0.35 
 1996     0.52 
 1997     0.32 
 1998      0.6 
 1999      0.9 
 2000     0.03 
 2001     0.47 
 2002      0.3 
 2003     0.55 
 2004     0.76 
 2005     0.65 
 2006     0.75 
 2007     0.54 
 2008     0.86 
 2009     0.12 
 2010     0.57 
 2011     0.74 
 2012     0.72 
 2013     0.69 
 2014     0.91 
 2015     0.43 
 2016        1 
 2017     0.77 
 2018      0.7