Year Percent 1997-01-01 2.78 1998-01-01 3.55 1999-01-01 5.46 2000-01-01 6.61 2001-01-01 7.12 2002-01-01 11.45 2003-01-01 11.51 2004-01-01 11.17 2005-01-01 11.66 2006-01-01 12.52 2007-01-01 10.50