Year Percent 1990 1.17373 1991 1.14981 1992 1.42341 1993 1.39308 1994 1.35036 1995 2.12235 1996 1.59625 1997 1.41448 1998 1.59631 1999 1.5535 2000 1.64294 2001 1.65872 2002 1.61808 2003 1.45843 2004 1.50192 2005 1.48249 2007 1.43471 2008 1.39123 2009 1.34946 2010 1.31996 2011 2.70826 2012 2.66478 2013 2.60836 2014 2.53678 2015 2.4531 2016 1.11572 2017 1.07466 2018 1.04051 2019 1.00563 2020 1.14407