Year Percent 1979-01-01 0.13153800000000002 1980-01-01 0.53460800000000000 1981-01-01 0.48784099999999997 1982-01-01 0.70572000000000000 1983-01-01 0.93438700000000010 1984-01-01 0.88879200000000000 1985-01-01 0.87601100000000010 1986-01-01 1.36819000000000000 1987-01-01 1.41519000000000000 1988-01-01 1.33174000000000000 1989-01-01 1.25260000000000000 1990-01-01 1.17925000000000000 1991-01-01 0.96357500000000000 1992-01-01 1.01758000000000000 1993-01-01 0.79463000000000010 1994-01-01 0.78092400000000000 1995-01-01 1.21312000000000000 1996-01-01 1.20421000000000000 1997-01-01 1.10824000000000000 1998-01-01 1.23480000000000000 1999-01-01 1.10767000000000020 2000-01-01 1.06296000000000010 2001-01-01 1.34085000000000000 2002-01-01 1.42849000000000000 2003-01-01 2.28340000000000000 2004-01-01 2.53908000000000000 2005-01-01 2.59173000000000000 2006-01-01 2.72126000000000000 2007-01-01 2.55343000000000000 2008-01-01 2.34610000000000000 2009-01-01 2.45274000000000040 2010-01-01 2.08737000000000000 2011-01-01 1.98610000000000000 2012-01-01 1.93230000000000000 2013-01-01 1.81952999999999990 2014-01-01 1.88697000000000000 2015-01-01 2.24287000000000000 2016-01-01 2.66419000000000000 2017-01-01 2.66257999999999970