Year Percent 1975-01-01 0.12779200000000002 1976-01-01 0.13141000000000000 1977-01-01 0.26216400000000000 1978-01-01 0.38980500000000000 1979-01-01 1.00057000000000020 1980-01-01 1.41812000000000000 1981-01-01 2.02548000000000000 1982-01-01 3.36711000000000000 1983-01-01 6.50415000000000000 1984-01-01 8.20002000000000000 1985-01-01 8.43647000000000000 1986-01-01 10.11330000000000000 1987-01-01 10.73040000000000000 1988-01-01 9.60902000000000000 1989-01-01 8.38456000000000000 1990-01-01 7.04034000000000000 1991-01-01 6.75034000000000000 1992-01-01 8.85369000000000000 1993-01-01 14.88070000000000000 1994-01-01 28.63770000000000000 1995-01-01 37.16130000000000000 1996-01-01 41.07070000000000000 1997-01-01 50.57340000000000000 1998-01-01 64.79280000000000000 1999-01-01 75.18370000000000000 2000-01-01 109.89500000000000000 2001-01-01 133.24900000000000000 2002-01-01 95.89490000000000000 2003-01-01 64.03040000000000000 2004-01-01 69.21180000000000000 2005-01-01 111.65100000000001000 2006-01-01 136.39900000000000000 2007-01-01 174.19900000000000000 2008-01-01 160.75600000000000000 2009-01-01 109.48299999999999000 2010-01-01 86.92070000000000000 2011-01-01 88.26370000000000000 2012-01-01 79.00720000000000000