Year Percent 1980-01-01 1.7075700000000000 1981-01-01 2.1090500000000000 1982-01-01 2.4506099999999997 1983-01-01 3.1369500000000000 1984-01-01 4.4934300000000000 1985-01-01 7.5307600000000010 1986-01-01 9.1729300000000010 1987-01-01 9.5089399999999990 1988-01-01 10.3519000000000000 1989-01-01 11.7333000000000000 1990-01-01 12.6197000000000000 1991-01-01 17.1672000000000000 1992-01-01 16.4956000000000000 1993-01-01 22.1329000000000000 1994-01-01 24.8052000000000000 1995-01-01 26.0783000000000000 1996-01-01 28.2849000000000000 1997-01-01 32.3428000000000000 1998-01-01 34.1906000000000000 1999-01-01 32.7036000000000000 2000-01-01 37.1266000000000000 2001-01-01 40.4985000000000000 2002-01-01 47.2223000000000000 2003-01-01 48.5977000000000000 2004-01-01 48.4334000000000000 2005-01-01 44.7064000000000000 2006-01-01 53.9844000000000000 2007-01-01 61.2807000000000000 2008-01-01 61.7728000000000000 2009-01-01 79.9514000000000000 2010-01-01 83.3334000000000000 2011-01-01 67.3429000000000000 2012-01-01 69.2055000000000000 2013-01-01 72.0169000000000000 2014-01-01 57.3158000000000000 2015-01-01 64.1696000000000000 2016-01-01 62.9506000000000000