Year Percent Change from Year Ago 1971-01-01 7.07549095659983 1972-01-01 3.82635552505150 1973-01-01 7.77281991957252 1974-01-01 2.33592312410550 1975-01-01 8.70419392970713 1976-01-01 -1.55993934845539 1977-01-01 7.57555719786846 1978-01-01 11.66376199532840 1979-01-01 7.59267414449655 1980-01-01 7.83273944238455 1981-01-01 5.11138772753409 1982-01-01 9.01936210211038 1983-01-01 10.76818159676550 1984-01-01 15.19287938222310 1985-01-01 13.43073328650400 1986-01-01 8.94909549852753 1987-01-01 11.65778539764920 1988-01-01 11.22303591338290 1989-01-01 4.20602011347721 1990-01-01 3.91976664247795 1991-01-01 9.26245380143289 1992-01-01 14.22489819687050 1993-01-01 13.88364863795400 1994-01-01 13.03646577414620 1995-01-01 10.95408027587860 1996-01-01 9.92262146368492 1997-01-01 9.23686493329895 1998-01-01 7.84595473978812 1999-01-01 7.66152985813492 2000-01-01 8.49001585079000 2001-01-01 8.33574709666865 2002-01-01 9.13365170708462 2003-01-01 10.03803804669340 2004-01-01 10.11367066741490 2005-01-01 11.39458128664710 2006-01-01 12.72098010398310 2007-01-01 14.23084409633640 2008-01-01 9.65066555885301 2009-01-01 9.39873590025138 2010-01-01 10.63588657791680 2011-01-01 9.53915222347726 2012-01-01 7.85675305721396 2013-01-01 7.75841116841354 2014-01-01 7.29486831810867 2015-01-01 6.90019255774250 2016-01-01 6.71985189137443