# year    value 
 1980 0.1523477 
 1981 -2.226012 
 1982 -1.138955 
 1983 -0.1412247 
 1984 -0.9238975 
 1985 -2.518817 
 1986 -1.216776 
 1987 -1.787001 
 1988 1.076534 
 1989 0.6194078 
 1990 1.400291 
 1991 -1.539144 
 1992 -0.5958141 
 1993 -0.1112839 
 1994 0.8519282 
 1995 0.981342 
 1996  -0.9006 
 1997 0.08692048 
 1998 1.531972 
 1999 -0.7994723 
 2000 -0.1355783 
 2001 1.240457 
 2002 -0.1626389 
 2003 -0.9988305 
 2004 -0.1939738 
 2005 -1.178258 
 2006 -1.897595 
 2007 2.494531 
 2008  1.01043 
 2009 -0.8671972 
 2010 -1.166418 
 2011 -0.6958476 
 2012 -0.832517 
 2013 -0.7870918 
 2014 1.983488 
 2015 0.6778787 
 2016 1.988801 
 2017 -0.003639658 
 2018 0.05536611