Year Percent 1961-01-01 7.1829800000000010 1962-01-01 7.5369399999999995 1963-01-01 9.0011700000000000 1964-01-01 9.3943700000000000 1965-01-01 8.5154100000000010 1966-01-01 7.3807700000000000 1967-01-01 7.5498699999999990 1968-01-01 8.2414399999999990 1969-01-01 8.7069500000000000 1970-01-01 10.0122000000000000 1971-01-01 10.8421000000000000 1972-01-01 11.6965000000000000 1973-01-01 13.1313000000000000 1974-01-01 13.0350000000000000 1975-01-01 12.9371000000000000 1976-01-01 13.3992000000000000 1977-01-01 14.2913000000000000 1978-01-01 16.8289000000000000 1979-01-01 17.1020000000000000 1980-01-01 13.7452000000000000 1981-01-01 10.6418000000000000 1982-01-01 9.6320500000000000 1983-01-01 8.8797300000000000 1984-01-01 8.6080600000000000 1985-01-01 8.9480600000000000 1986-01-01 9.0280300000000010 1987-01-01 8.4387300000000000 1988-01-01 7.9094200000000000 1989-01-01 12.5708000000000000 1990-01-01 12.5708000000000000 1991-01-01 27.7557000000000000 1992-01-01 55.7991000000000000 1993-01-01 87.3027000000000000 1994-01-01 132.3520000000000000 1995-01-01 147.9020000000000200 1996-01-01 72.5885000000000000 1997-01-01 23.3346000000000000 1998-01-01 171.1430000000000000 1999-01-01 231.8970000000000200 2000-01-01 112.7560000000000000 2001-01-01 126.7410000000000000 2002-01-01 157.1720000000000000 2003-01-01 221.4920000000000200 2004-01-01 222.5750000000000000 2005-01-01 260.2009999999999600 2006-01-01 314.4980000000000000 2007-01-01 378.7920000000000000 2008-01-01 528.8640000000000000 2009-01-01 724.3470000000000000 2010-01-01 906.3830000000000000 2011-01-01 14.3439000000000000 2012-01-01 14.9720000000000010 2013-01-01 16.6653000000000000