Year Percent 1984-01-01 1.9919700000000000 1985-01-01 2.0171300000000000 1986-01-01 2.4389800000000000 1987-01-01 2.5498800000000000 1988-01-01 2.4254200000000000 1989-01-01 2.9542300000000000 1990-01-01 4.1159099999999995 1991-01-01 6.9036300000000010 1992-01-01 8.8373900000000000 1993-01-01 10.6923000000000000 1994-01-01 13.0921000000000000 1995-01-01 12.6242000000000000 1996-01-01 11.9341000000000000 1997-01-01 10.9863000000000000 1998-01-01 9.5294600000000000 1999-01-01 8.7767699999999990 2000-01-01 8.8670600000000000 2001-01-01 9.8016700000000000 2002-01-01 10.9025000000000000 2003-01-01 12.9972000000000000 2004-01-01 14.3726000000000000 2005-01-01 14.2616000000000000 2006-01-01 14.6653000000000000 2007-01-01 15.6966000000000000 2008-01-01 16.1857000000000000 2009-01-01 26.9304000000000000 2010-01-01 37.1594000000000000 2011-01-01 39.3603000000000000 2012-01-01 39.7764000000000000 2013-01-01 38.9752000000000000 2014-01-01 39.3967000000000000 2015-01-01 40.7326000000000000 2016-01-01 44.2086000000000000