Year annual % 1973 4.124310194597734 1974 82.8966849050531 1975 38.41551402527013 1976 39.50366151342555 1977 25.496378924856618 1978 11.646664116926562 1979 6.766284787567104 1980 31.998879042149643 1981 38.672020430454914 1982 26.665276209198762 1983 23.417631715857752 1984 9.857313786187838 1985 21.05379436513812 1986 -6.779585040983606 1987 5.272726856399653 1988 5.938931496957015 1989 9.411456729288574 1990 9.969252479646306 1991 5.451836860413625 1992 3.088863069250213 1993 3.246526960207205 1994 6.734505847366405 1995 7.677340045325892 1996 8.072504643323931 1997 24.498498064743572 1998 4.770198768933389 1999 6.393284550289626 2000 6.0240560027766765 2001 10.804050827519537 2002 5.554986190712696 2003 2.422397359660853 2004 4.080875816702965 2005 21.654062392823636 2006 24.44983537431159 2007 34.67018899930939 2008 23.266197765856493 2009 4.734999080074412 2010 11.342093861885537 2011 12.181146406553708 2012 10.727015497411058 2013 8.485305980606206 2014 12.029358302555519 2015 14.210084356508718 2016 1.830874477608218 2017 4.181722141600611