Year Percent 1990 1.98564 1991 2.00983 1992 2.30012 1993 2.58633 1994 3.05896 1995 2.90635 1996 3.01658 1997 3.12804 1998 2.9979 1999 2.674 2000 2.42458 2001 1.98563 2002 1.85517 2003 1.92571 2004 2.21459 2005 2.1577 2006 2.16867 2007 1.88342 2008 1.65684 2009 2.08901 2010 2.27577 2011 2.26003 2012 2.39286 2013 2.5525 2014 2.85516 2015 2.90008 2016 2.80474 2017 2.60005