Year Percent 1980-01-01 4.1935500000000000 1981-01-01 4.6966900000000000 1982-01-01 3.2437800000000000 1983-01-01 2.2010400000000003 1984-01-01 1.8645100000000000 1985-01-01 2.7170900000000002 1986-01-01 1.9038099999999998 1987-01-01 2.5737900000000002 1988-01-01 3.6572300000000000 1989-01-01 3.5872599999999997 1990-01-01 2.6177000000000000 1991-01-01 9.2049100000000000 1992-01-01 10.4719000000000000 1993-01-01 12.3752000000000000 1994-01-01 12.1733000000000000 1995-01-01 11.6538000000000000 1996-01-01 11.7292000000000000 1997-01-01 10.2083000000000000 1998-01-01 9.9832300000000000 1999-01-01 10.0654000000000000 2000-01-01 8.0523400000000000 2001-01-01 13.1614000000000000 2002-01-01 25.4948000000000000 2003-01-01 27.4936000000000000 2004-01-01 12.2620000000000000 2005-01-01 11.4883000000000000 2006-01-01 11.6649000000000000 2007-01-01 10.5534000000000000 2008-01-01 13.6089000000000000 2009-01-01 14.4755000000000000 2010-01-01 14.4845000000000000 2011-01-01 13.8970000000000000 2012-01-01 13.0765000000000000 2013-01-01 14.1339000000000000 2014-01-01 16.1465000000000000 2015-01-01 16.2738000000000000 2016-01-01 19.5342000000000000