Year Percent 1990 2.68647 1991 2.50264 1992 1.9357 1993 1.70471 1994 1.27044 1995 1.12327 1996 1.10099 1997 1.05105 1998 1.02355 1999 0.95503 2000 0.88984 2001 0.91293 2002 0.89804 2003 0.92676 2004 0.80253 2005 0.79971 2006 0.86081 2007 0.82473 2008 0.81635 2009 0.82302 2010 0.73021 2011 0.69821 2012 0.62513 2013 0.75574 2014 0.75518 2015 0.72852 2016 0.67638 2017 0.62914 2018 0.61236 2019 0.50054 2020 0.46447