Year Percent 1989-01-01 53.05470000000000 1990-01-01 64.62680000000000 1991-01-01 80.17780000000000 1992-01-01 81.36840000000000 1993-01-01 83.43080000000000 1994-01-01 86.44190000000000 1995-01-01 87.25710000000000 1996-01-01 87.83700000000000 1997-01-01 81.68260000000000 1998-01-01 73.50460000000000 1999-01-01 66.00550000000000 2000-01-01 65.73060000000000 2001-01-01 69.06400000000000 2002-01-01 68.33460000000000 2003-01-01 67.86399999999999 2004-01-01 70.40490000000000 2005-01-01 77.34630000000000 2006-01-01 80.01310000000000 2007-01-01 77.74670000000000 2008-01-01 78.03990000000000 2009-01-01 75.92490000000000 2010-01-01 75.73140000000000