Year Percent 1987-01-01 1.1589700000000000 1988-01-01 2.2298500000000000 1989-01-01 1.6645000000000000 1990-01-01 1.6645000000000000 1991-01-01 1.1903200000000000 1992-01-01 1.0520399999999999 1993-01-01 1.3126500000000000 1994-01-01 1.8113200000000000 1995-01-01 1.7750099999999998 1996-01-01 1.6364000000000000 1997-01-01 2.2857000000000000 1998-01-01 2.1147299999999998 1999-01-01 2.3855900000000000 2000-01-01 1.8146799999999998 2001-01-01 1.1553200000000001 2002-01-01 1.1553200000000001 2003-01-01 1.1553200000000001 2004-01-01 1.0005300000000000 2005-01-01 0.7986570000000000 2006-01-01 3.1508800000000000 2007-01-01 2.7603800000000000 2008-01-01 1.9164800000000000 2009-01-01 1.9688000000000000 2010-01-01 2.1425300000000000 2011-01-01 1.8273900000000000 2012-01-01 1.6756400000000002 2013-01-01 2.6964200000000003 2014-01-01 3.4112600000000000 2015-01-01 6.6999600000000010 2016-01-01 18.6370000000000000