Year Percent 1990 69.339 1991 69.989 1992 71.059 1993 72.234 1994 73.711 1995 74.225 1996 74.017 1997 73.629 1998 73.613 1999 73.502 2000 73.288 2001 73.069 2002 73.128 2003 73.274 2004 73.387 2005 73.997 2006 74.58 2007 73.042 2008 71.431 2009 69.736 2010 70.173 2011 70.024 2012 69.401 2013 64.437 2014 66.331 2015 65.121 2016 63.674 2017 63.438 2018 63.24 2019 63.078 2020 62.949 2021 62.853 2022 62.791 2023 62.758 2024 62.742 2025 62.734 2026 62.73 2027 62.731 2028 62.724 2029 62.69 2030 62.614