Year Percent 1991-01-01 163.94299999999998 1992-01-01 152.64900000000000 1993-01-01 146.26400000000000 1994-01-01 145.98500000000000 1995-01-01 153.69000000000000 1996-01-01 154.93400000000000 1997-01-01 154.14200000000000 1998-01-01 180.49900000000002 1999-01-01 199.01100000000000 2000-01-01 206.94400000000002 2001-01-01 221.38099999999997 2002-01-01 223.72500000000000 2003-01-01 235.95700000000000 2004-01-01 240.95000000000000 2005-01-01 237.00400000000002 2006-01-01 245.91700000000000 2007-01-01 261.65500000000000 2008-01-01 284.98400000000004 2009-01-01 302.74000000000000 2010-01-01 300.18100000000000 2011-01-01 301.75200000000000 2012-01-01 309.31000000000000 2013-01-01 320.76599999999996 2014-01-01 331.10600000000000 2015-01-01 334.55100000000000 2016-01-01 347.38699999999994