Year Percent 1991-01-01 4.84700012207031 1992-01-01 4.83300018310547 1993-01-01 4.88100004196167 1994-01-01 4.76599979400635 1995-01-01 4.77400016784668 1996-01-01 5.04899978637695 1997-01-01 5.25500011444092 1998-01-01 5.63999986648560 1999-01-01 5.84499979019165 2000-01-01 5.97100019454956 2001-01-01 6.53200006484985 2002-01-01 6.88999986648560 2003-01-01 7.13999986648560 2004-01-01 7.53800010681152 2005-01-01 8.10000038146973 2006-01-01 8.48600006103516 2007-01-01 9.00199985504150 2008-01-01 12.30900001525880 2009-01-01 11.51299953460690 2010-01-01 10.51099967956540 2011-01-01 9.33300018310547 2012-01-01 8.42700004577637 2013-01-01 7.52500009536743 2014-01-01 6.73600006103516 2015-01-01 5.87300014495850 2016-01-01 4.90000009536743 2017-01-01 4.92899990081787