Year Percent 1990-01-01 4.9092000000000000 1991-01-01 4.3728600000000000 1992-01-01 4.0661600000000000 1993-01-01 4.0604700000000000 1994-01-01 3.7213400000000000 1995-01-01 3.4446100000000000 1996-01-01 2.9339800000000000 1997-01-01 3.8613699999999995 1998-01-01 4.6538200000000000 1999-01-01 4.9905200000000000 2000-01-01 4.8606300000000005 2001-01-01 4.9895900000000000 2002-01-01 5.2822800000000000 2003-01-01 5.6174200000000000 2004-01-01 6.2076000000000000 2005-01-01 6.2604400000000000 2006-01-01 6.3424300000000000 2007-01-01 6.8925600000000005 2008-01-01 7.4420699999999990 2009-01-01 7.9091200000000000 2010-01-01 5.9841200000000000 2011-01-01 5.6981900000000000 2012-01-01 4.5110500000000000 2013-01-01 4.8382000000000000