Year Percent 1980-01-01 1.8526700000000000 1981-01-01 2.3533500000000000 1982-01-01 3.8294599999999996 1983-01-01 3.8681000000000000 1984-01-01 4.4531300000000010 1985-01-01 6.8784600000000005 1986-01-01 7.2904700000000000 1987-01-01 18.1266000000000000 1988-01-01 13.4656000000000000 1989-01-01 12.3191000000000000 1990-01-01 14.5057000000000000 1991-01-01 13.7848000000000000 1992-01-01 11.5838000000000000 1993-01-01 5.2890300000000000 1994-01-01 4.7677800000000000 1995-01-01 5.3434700000000000 1996-01-01 5.8993000000000000 1997-01-01 7.2387600000000010 1998-01-01 9.0449399999999990 1999-01-01 8.6252200000000000 2000-01-01 10.1253000000000000 2001-01-01 11.6940000000000000 2002-01-01 11.2055000000000000 2003-01-01 8.1789300000000010 2004-01-01 8.6476899999999990 2005-01-01 5.1797400000000000 2006-01-01 5.3023900000000000 2007-01-01 6.4035699999999990 2008-01-01 5.1565400000000010 2009-01-01 7.5898300000000000 2010-01-01 9.1635800000000000 2011-01-01 11.4144000000000000 2012-01-01 12.7448000000000000 2013-01-01 12.1808000000000000 2014-01-01 9.5289000000000000 2015-01-01 11.0035000000000000 2016-01-01 7.4496699999999990