Year Percent 1991-01-01 3.93499994277954 1992-01-01 4.04799985885620 1993-01-01 4.02199983596802 1994-01-01 4.03999996185303 1995-01-01 3.87199997901917 1996-01-01 3.87800002098084 1997-01-01 3.90400004386902 1998-01-01 3.88899993896484 1999-01-01 3.86400008201599 2000-01-01 4.71000003814697 2001-01-01 5.11800003051758 2002-01-01 4.97100019454956 2003-01-01 4.73299980163574 2004-01-01 6.52500009536743 2005-01-01 8.15200042724609 2006-01-01 8.30599975585938 2007-01-01 9.95400047302246 2008-01-01 10.35499954223630 2009-01-01 12.59899997711180 2010-01-01 8.59500026702881 2011-01-01 9.10799980163574 2012-01-01 6.98099994659424 2013-01-01 9.34099960327148 2014-01-01 9.20899963378906 2015-01-01 10.00000000000000 2016-01-01 10.12600040435790 2017-01-01 10.18999958038330