Year Percent 1980-01-01 0.45044600000000000 1981-01-01 0.70766200000000000 1982-01-01 1.44225000000000000 1983-01-01 1.10716000000000010 1984-01-01 0.85613100000000000 1985-01-01 1.14073000000000000 1986-01-01 0.75460100000000010 1987-01-01 0.62569900000000000 1988-01-01 0.45221400000000006 1989-01-01 0.37790799999999997 1990-01-01 0.11319200000000000 1991-01-01 0.46878200000000000 1992-01-01 0.96899400000000000 1993-01-01 12.99780000000000000 1994-01-01 13.80540000000000000 1995-01-01 15.69410000000000000 1996-01-01 18.43370000000000000 1997-01-01 20.84270000000000000 1998-01-01 22.57550000000000000 1999-01-01 26.21350000000000000 2000-01-01 28.20490000000000000 2001-01-01 30.88940000000000000 2002-01-01 82.70680000000000000 2003-01-01 67.49140000000000000 2004-01-01 56.14720000000000000 2005-01-01 28.78199999999999600 2006-01-01 25.92630000000000000 2007-01-01 21.87050000000000000 2008-01-01 14.03360000000000000 2009-01-01 15.02170000000000000 2010-01-01 11.96780000000000000 2011-01-01 9.64542000000000000 2012-01-01 8.73259000000000000 2013-01-01 8.56622000000000000 2014-01-01 8.84313000000000000 2015-01-01 7.81868999999999900 2016-01-01 15.03270000000000000