Year Percent 1971-01-01 0.382876000000000000 1972-01-01 0.447331999999999950 1973-01-01 0.447331999999999950 1974-01-01 0.241281000000000000 1975-01-01 0.294969999999999950 1976-01-01 0.567876000000000000 1977-01-01 0.554815000000000000 1978-01-01 0.666977000000000000 1979-01-01 0.368554000000000000 1980-01-01 -0.014902000000000000 1981-01-01 0.390584000000000040 1982-01-01 0.276346999999999950 1983-01-01 -0.050966000000000004 1984-01-01 0.245623999999999980 1985-01-01 -0.259326000000000000 1986-01-01 0.218790000000000000 1987-01-01 0.719102000000000000 1988-01-01 0.516942000000000000 1989-01-01 0.278840000000000030 1990-01-01 1.346830000000000000 1991-01-01 1.227060000000000000 1992-01-01 2.885670000000000000 1993-01-01 -1.201039999999999900 1994-01-01 -0.006775000000000000 1995-01-01 -1.008200000000000000 1996-01-01 0.719155000000000000 1997-01-01 -1.112490000000000000 1998-01-01 -1.496230000000000000 1999-01-01 0.044370000000000000 2000-01-01 -0.898519000000000100 2001-01-01 -0.041006000000000000 2002-01-01 0.555345000000000000 2003-01-01 -1.262050000000000000 2004-01-01 0.661185000000000000 2005-01-01 0.503336000000000000 2006-01-01 0.215652000000000000 2007-01-01 -1.001229999999999800 2008-01-01 0.923372000000000000 2009-01-01 1.007960000000000000 2010-01-01 1.723570000000000000 2011-01-01 0.078561000000000000 2012-01-01 1.545729999999999800 2013-01-01 1.479000000000000000 2014-01-01 0.404242000000000000 2015-01-01 -0.560945000000000000 2016-01-01 1.778550000000000000