Year Percent 1960-01-01 3.384615384615520 1961-01-01 2.511321531006940 1962-01-01 0.168674698957622 1963-01-01 1.876353139212690 1964-01-01 2.180243998596840 1965-01-01 1.602218456101320 1966-01-01 0.523123578699539 1967-01-01 0.693868315713028 1968-01-01 2.037300576822770 1969-01-01 2.334287601862220 1970-01-01 3.715658848092590 1971-01-01 2.323812158388100 1972-01-01 3.372761067811540 1973-01-01 7.689289917861470 1974-01-01 7.255616272040100 1975-01-01 8.791666666166900 1976-01-01 0.551512830258580 1977-01-01 10.040374800236400 1978-01-01 4.707511249514880 1979-01-01 7.147107437978910 1980-01-01 15.747254103486000 1981-01-01 11.509755837712300 1982-01-01 5.818233972186680 1983-01-01 -0.880997560317525 1984-01-01 -0.442500000750074 1985-01-01 -0.235207459677486 1986-01-01 2.027888714147630 1987-01-01 0.431725669422428 1988-01-01 0.938344387128529 1989-01-01 0.847691359226220 1990-01-01 2.983405860635590 1991-01-01 2.542192847869760 1992-01-01 1.633212098890450 1993-01-01 4.144819541804900 1994-01-01 4.129921816382570 1995-01-01 4.426645502866550 1996-01-01 2.054000000000080 1997-01-01 3.112077919532710 1998-01-01 2.385251354176630 1999-01-01 2.134768888063850 2000-01-01 2.369592875318110 2001-01-01 2.929492443241010 2002-01-01 2.188490480605480 2003-01-01 1.303837774426020 2004-01-01 2.790828480677530 2005-01-01 3.007966524503180 2006-01-01 2.773264170989310 2007-01-01 1.251349406261230 2008-01-01 4.256736945917860 2009-01-01 2.085357331560730 2010-01-01 1.516833766038280 2011-01-01 2.721905169152830 2012-01-01 2.417624643760600 2013-01-01 1.374906203101570 2014-01-01 0.311500057827987 2015-01-01 1.099931590557960 2016-01-01 0.638020508792792 2017-01-01 1.364354481507090