Year Percent 1960-01-01 1.65082000000000020 1961-01-01 1.36424000000000000 1962-01-01 1.03347000000000000 1963-01-01 0.79160100000000000 1964-01-01 0.72664600000000000 1965-01-01 0.79884100000000000 1966-01-01 1.42536000000000000 1967-01-01 2.36670000000000000 1968-01-01 2.35698000000000000 1969-01-01 1.55781000000000010 1970-01-01 1.05257999999999980 1971-01-01 0.85635000000000000 1972-01-01 0.80203900000000010 1973-01-01 0.76738000000000010 1974-01-01 0.89486800000000000 1975-01-01 1.19989000000000000 1976-01-01 1.44839000000000000 1977-01-01 1.49851000000000000 1978-01-01 1.34883000000000000 1979-01-01 1.34067000000000000 1980-01-01 1.55877999999999980 1981-01-01 1.83645999999999980 1982-01-01 1.99741000000000000 1983-01-01 2.19687000000000000 1984-01-01 2.21957000000000000 1985-01-01 1.92422000000000000 1986-01-01 1.70204000000000020 1987-01-01 1.58537000000000020 1988-01-01 1.36912000000000010 1989-01-01 1.19132000000000020 1990-01-01 1.02255000000000000 1991-01-01 0.93138600000000000 1992-01-01 0.97506200000000010 1993-01-01 1.14211000000000000 1994-01-01 1.11089000000000000 1995-01-01 0.93647099999999990 1996-01-01 0.79118400000000000 1997-01-01 0.62913200000000000 1998-01-01 0.52594800000000000 1999-01-01 0.34575500000000003 2000-01-01 0.15455900000000000 2001-01-01 0.07325599999999999 2002-01-01 0.04767100000000000 2003-01-01 0.01359400000000000 2004-01-01 0.00441600000000000 2005-01-01 0.00426200000000000 2006-01-01 0.09341900000000000 2007-01-01 0.20000000000000000 2008-01-01 0.21859600000000000 2009-01-01 0.28950200000000000 2010-01-01 0.31100900000000004 2011-01-01 0.24090500000000000 2012-01-01 0.16762200000000000 2013-01-01 0.13271100000000000 2014-01-01 0.20761000000000000 2015-01-01 1.95394000000000020 2016-01-01 6.21004000000000000