# year    value 
 1980 0.8688138 
 1981 2.176763 
 1982 -0.2027632 
 1983  0.76862 
 1984 -1.141135 
 1985 -2.139565 
 1986 0.8036355 
 1987 -0.01820914 
 1988 -0.6045561 
 1989 -1.813419 
 1990 -0.0004479165 
 1991 -0.7948667 
 1992 0.7998272 
 1993 -2.001576 
 1994 0.4549537 
 1995 1.725392 
 1996  1.11618 
 1997 0.1441698 
 1998 0.5072102 
 1999 0.9109263 
 2000 1.594149 
 2001 -0.6847473 
 2002 0.04242529 
 2003 1.572622 
 2004 0.02867938 
 2005 0.9918342 
 2006 1.220088 
 2007 -0.2624044 
 2008 -0.4992281 
 2009 0.2311026 
 2010 -0.629586 
 2011 -0.05267821 
 2012 0.4758379 
 2013 -0.4138961 
 2014 0.1106166 
 2015 2.420699 
 2016 1.369991 
 2017 -0.1839181 
 2018 1.004084