Year Percent 1998-01-01 0.000000 1999-01-01 3.891632 2000-01-01 0.000000 2001-01-01 553.017800 2002-01-01 526.768800 2003-01-01 531.411400 2004-01-01 620.060600 2005-01-01 658.604500 2006-01-01 746.687100 2007-01-01 885.671400