Year Percent 1990 1.03037 1991 1.63439 1992 1.39291 1993 1.62973 1994 1.64134 1995 2.45315 1996 2.62739 1997 2.56147 1998 2.50288 1999 2.39493 2000 2.40464 2001 1.5617 2002 1.72832 2003 1.76524 2004 1.76371 2005 1.83166 2006 1.56996 2007 1.58763 2008 1.62204 2009 1.62387 2010 1.64472 2011 1.64934 2012 1.64138 2013 1.64895 2014 1.6436 2015 1.65119 2016 1.67354 2017 1.39147 2018 1.40681 2019 1.40433 2020 1.43686