Year Percent 1990 53.433 1991 53.167 1992 52.907 1993 52.723 1994 52.434 1995 52.173 1996 51.956 1997 52.922 1998 51.468 1999 49.716 2000 48.869 2001 49.821 2002 51.052 2003 50.553 2004 50.432 2005 50.435 2006 52.015 2007 52.915 2008 54.83 2009 54.365 2010 53.85 2011 53.017 2012 54.222 2013 53.924 2014 53.448 2015 54.26 2016 55.28 2017 55.209 2018 55.038 2019 54.793 2020 54.489 2021 54.147 2022 53.756 2023 53.342 2024 52.95 2025 52.611 2026 52.338 2027 52.155 2028 52.045 2029 51.975 2030 51.922