Year Percent 1990-01-01 26.8441 1991-01-01 26.0824 1992-01-01 24.5072 1993-01-01 28.9024 1994-01-01 37.5712 1995-01-01 41.8835 1996-01-01 44.2979 1997-01-01 45.8687 1998-01-01 47.7869 1999-01-01 46.0139 2000-01-01 43.7355 2001-01-01 42.7037 2002-01-01 42.4080 2003-01-01 42.0668 2004-01-01 38.9767 2005-01-01 33.4989 2006-01-01 29.7186 2007-01-01 28.6411 2008-01-01 28.1080 2009-01-01 35.1108 2010-01-01 43.1494 2011-01-01 45.2813