# year    value 
 1979 -4.014012 
 1980 0.6797793 
 1981 1.996396 
 1982 -0.7830065 
 1983 1.175349 
 1984 -0.9853825 
 1985 -1.919721 
 1986 0.6643323 
 1987 0.8221191 
 1988 -0.5232678 
 1989 -1.173397 
 1990 0.2037421 
 1991 -0.3332841 
 1992 1.721186 
 1993 -1.759295 
 1994 -0.2231703 
 1995 1.487918 
 1996 0.3385574 
 1997 -0.3524478 
 1998 0.8964767 
 1999 1.236382 
 2000 1.991041 
 2001 -1.162367 
 2002 0.5347001 
 2003 1.038134 
 2004 0.103503 
 2005 1.207809 
 2006 1.539953 
 2007 -0.04664111 
 2008 -0.5046389 
 2009 0.2144327 
 2010 -1.131853 
 2011 -0.4446209 
 2012 1.291771 
 2013 0.02978084 
 2014 -0.485228 
 2015 1.921764 
 2016 1.789413 
 2017 0.5799525 
 2018 0.7193102