# year    value 
 1979 1.851036 
 1980 0.9916294 
 1981 1.482816 
 1982 1.015361 
 1983 0.4030517 
 1984 -0.2825502 
 1985 0.3433636 
 1986 0.8527847 
 1987 1.948116 
 1988 1.548257 
 1989 1.195965 
 1990 1.733104 
 1991 1.282099 
 1992 1.129822 
 1993 1.571127 
 1994 1.173153 
 1995 1.213722 
 1996 0.6233139 
 1997 1.312626 
 1998 1.151177 
 1999 2.781898 
 2000 0.9867271 
 2001 1.759603 
 2002 2.295437 
 2003 1.603864 
 2004 1.970632 
 2005 1.013366 
 2006 1.874759 
 2007 2.219548 
 2008 0.1113896 
 2009 2.734708 
 2010 1.796904 
 2011 0.7890267 
 2012 0.1894143 
 2013 1.246355 
 2014 1.153561 
 2015 2.099246 
 2016   2.0272 
 2017 2.975677 
 2018 1.873761