Year Percent 1993-01-01 3.5904599999999998 1994-01-01 3.5904599999999998 1995-01-01 4.8903800000000000 1996-01-01 5.6361700000000000 1997-01-01 6.1136900000000000 1998-01-01 7.5074700000000000 1999-01-01 12.1023000000000000 2000-01-01 15.8782000000000000 2001-01-01 17.8335000000000000 2002-01-01 16.0150000000000000 2003-01-01 2.8863900000000000 2004-01-01 5.3503600000000000 2005-01-01 7.4305100000000010 2006-01-01 7.2879399999999990 2007-01-01 7.5323699999999990 2008-01-01 6.7097000000000000 2009-01-01 5.2717199999999990 2010-01-01 4.1207000000000000 2011-01-01 3.5606800000000005 2012-01-01 3.8107900000000003