Year Percent 1990 65.477 1991 66.044 1992 66.484 1993 67.068 1994 67.682 1995 68.298 1996 68.833 1997 69.409 1998 70.094 1999 70.763 2000 71.405 2001 72.009 2002 72.595 2003 73.17 2004 73.736 2005 74.285 2006 74.81 2007 72.239 2008 74.516 2009 74.472 2010 74.048 2011 73.593 2012 72.036 2013 71.319 2014 72.196 2015 66.374 2016 66.911 2017 67.038 2018 67.166 2019 67.295 2020 67.424 2021 67.551 2022 67.679 2023 67.807 2024 67.938 2025 68.072 2026 68.208 2027 68.348 2028 68.493 2029 68.64 2030 68.79