Year Percent 1960 2.02674 1961 1.98647 1962 2.85734 1963 2.77796 1964 2.70287 1965 2.63173 1966 2.56424 1967 2.58827 1968 2.43702 1969 2.37904 1970 2.32376 1971 2.27098 1972 2.45557 1973 2.32029 1974 2.34238 1975 2.21575 1976 2.23917 1977 2.12022 1978 2.0762 1979 2.10106 1980 1.9921 1981 2.01764 1982 1.91454 1983 2.00257 1984 2.02399 1985 2.10281 1986 2.0595 1987 2.075 1988 2.14455 1989 1.99012 1990 1.89759 1991 1.91495 1992 1.7755 1993 1.69365 1994 1.61538 1995 1.5897 1996 1.46774 1997 1.30279 1998 -5.92473 1999 -10.95515 2000 -3.58213 2001 0.06786 2002 0.06793 2003 0.06788 2004 0.06784 2005 0.06791 2006 0.8032 2007 0.80326 2008 0.80321 2009 0.80317 2010 0.80325 2011 0.85907 2012 0.78973 2013 1.04153 2014 -0.12617 2015 -1.10389 2016 0.79602 2017 0.7952