Year Percent 1990-01-01 1.5622000000000000 1991-01-01 1.4598300000000000 1992-01-01 1.5879000000000000 1993-01-01 2.1765700000000000 1994-01-01 2.9984200000000000 1995-01-01 2.1768500000000000 1996-01-01 2.2763400000000003 1997-01-01 2.8693200000000000 1998-01-01 4.0820900000000000 1999-01-01 4.0254000000000000 2000-01-01 4.5247300000000000 2001-01-01 3.0518600000000000 2002-01-01 1.6136600000000000 2003-01-01 1.2502500000000000 2004-01-01 0.8739230000000000 2005-01-01 0.9225020000000000 2006-01-01 1.5881600000000000 2007-01-01 2.5009099999999997 2008-01-01 3.7391400000000004 2009-01-01 5.0615900000000000 2010-01-01 5.6763000000000000 2011-01-01 7.7533800000000000 2012-01-01 11.8017000000000000 2013-01-01 12.7012000000000000 2014-01-01 12.1196000000000000 2015-01-01 10.0475000000000000 2016-01-01 7.8316399999999990