Year Percent 1972 0.04469 1973 0.03662 1974 -0.0564 1978 -0.04026 1981 0.02403 1982 0.02081 1983 -0.01764 1984 -0.01559 1985 -0.07124 1986 0.01397 1987 0.01245 1988 0.01155 1989 0.04171 1990 0.00244 1991 0.02482 1992 0.02918 1993 0.01232 1994 0.03794 1995 0.03519 1996 0.00524 1997 0.04794 1998 0.00826 1999 0.0109 2000 0.12571 2001 0.0252 2002 0.02735 2003 0.01979 2004 0.01287 2005 0.03821 2006 0.09616 2007 0.05215 2008 0.09408 2009 0.17724 2010 0.16811 2011 0.04652 2012 0.02985 2013 0.04658 2014 0.0458 2015 0.07206 2016 0.57442 2017 0.14271