# year    value 
 1979 0.1592027 
 1980 1.951419 
 1981 -0.4856536 
 1982 0.6928616 
 1983 1.740716 
 1984 0.8847979 
 1985 -0.8338956 
 1986 0.5635746 
 1987 -0.002716144 
 1988 2.943434 
 1989  2.46727 
 1990 3.170828 
 1991 0.05803815 
 1992 0.9925916 
 1993 1.443739 
 1994 2.730711 
 1995 3.007643 
 1996 0.7811074 
 1997 1.759245 
 1998 3.213988 
 1999 0.9699196 
 2000 1.735579 
 2001 3.296701 
 2002 1.589059 
 2003 0.7855256 
 2004 1.715857 
 2005 0.7202429 
 2006 0.1923647 
 2007 4.539903 
 2008 2.854304 
 2009 1.171312 
 2010 0.9273494 
 2011 1.297745 
 2012 1.229374 
 2013 1.371508 
 2014 4.054604 
 2015 2.846897 
 2016  4.13802 
 2017 1.606272 
 2018 2.309866