Year Percent 1980-01-01 0.12863600000000000 1981-01-01 0.34486999999999995 1982-01-01 0.77146200000000000 1983-01-01 0.59438900000000010 1984-01-01 0.52156900000000000 1985-01-01 0.71269200000000000 1986-01-01 0.41215500000000000 1987-01-01 0.25095800000000000 1988-01-01 0.17739600000000000 1989-01-01 0.18052900000000000 1990-01-01 0.11319200000000000 1991-01-01 0.22563800000000000 1992-01-01 0.66656200000000000 1993-01-01 2.09909000000000030 1994-01-01 2.94138000000000000 1995-01-01 2.88238000000000000 1996-01-01 3.24131000000000000 1997-01-01 4.11510000000000000 1998-01-01 4.82299000000000000 1999-01-01 4.95050999999999950 2000-01-01 4.33928000000000050 2001-01-01 3.99440000000000000 2002-01-01 8.65932000000000000 2003-01-01 5.57166000000000000 2004-01-01 3.91268000000000040 2005-01-01 2.90596000000000000 2006-01-01 2.89047000000000000 2007-01-01 2.69020000000000000 2008-01-01 1.53100000000000000 2009-01-01 1.60751000000000000 2010-01-01 1.39465000000000000 2011-01-01 1.29282000000000000 2012-01-01 1.07046000000000000 2013-01-01 1.15944000000000000 2014-01-01 1.42103999999999990 2015-01-01 1.62140000000000000 2016-01-01 2.69929000000000000