Year Percent 1980-01-01 2.22503000000000000 1981-01-01 1.67465000000000000 1982-01-01 1.21177000000000000 1983-01-01 0.82883400000000000 1984-01-01 0.71414800000000000 1985-01-01 0.72923700000000000 1986-01-01 0.47540400000000000 1987-01-01 0.51444899999999990 1988-01-01 0.09734500000000000 1989-01-01 0.09734500000000000 1990-01-01 0.09734500000000000 1991-01-01 0.09734500000000000 1992-01-01 0.09734500000000000 1993-01-01 0.09734500000000000 1994-01-01 0.09734500000000000 1995-01-01 0.09734500000000000 1996-01-01 0.09734500000000000 1997-01-01 0.09734500000000000 1998-01-01 0.09734500000000000 1999-01-01 0.09734500000000000 2000-01-01 0.09734500000000000 2001-01-01 0.30520100000000000 2002-01-01 0.30247700000000000 2003-01-01 0.31155400000000000 2004-01-01 0.28007300000000000 2005-01-01 0.24830500000000003 2006-01-01 0.22577900000000000 2007-01-01 0.20274200000000000 2008-01-01 0.21685900000000002 2009-01-01 0.20546900000000000