Year Percent 1987-01-01 896.141000000000100 1988-01-01 358.620000000000000 1989-01-01 18.130500000000000 1990-01-01 18.130500000000000 1991-01-01 18.130500000000000 1992-01-01 22.772100000000000 1993-01-01 21.342300000000000 1994-01-01 19.473600000000000 1995-01-01 19.128700000000000 1996-01-01 16.428600000000000 1997-01-01 15.571700000000000 1998-01-01 15.714000000000000 1999-01-01 16.813800000000000 2000-01-01 20.854900000000000 2001-01-01 18.934700000000000 2002-01-01 20.019300000000000 2003-01-01 22.764600000000000 2004-01-01 21.878300000000000 2005-01-01 21.022000000000000 2006-01-01 24.813300000000000 2007-01-01 23.491999999999997 2008-01-01 26.320800000000000 2009-01-01 30.729500000000000 2010-01-01 35.047800000000000 2011-01-01 36.521800000000000 2012-01-01 37.735800000000000 2013-01-01 41.957000000000000 2014-01-01 45.402400000000000 2015-01-01 49.313900000000000 2016-01-01 50.556999999999995