Year Percent 1990 48.373 1991 55.229 1992 54.945 1993 54.688 1994 55.709 1995 56.671 1996 59.122 1997 59.841 1998 60.531 1999 61.213 2000 60.216 2001 61.347 2002 62.459 2003 64.884 2004 67.221 2005 69.486 2006 69.351 2007 68.048 2008 69.349 2009 68.267 2010 69.409 2011 69.835 2012 70.211 2013 70.55 2014 71.912 2015 70.237 2016 69.942 2017 70.392 2018 70.843 2019 71.274 2020 71.669 2021 72.037 2022 72.37 2023 72.679 2024 72.977 2025 73.273 2026 73.567 2027 73.856 2028 74.138 2029 74.415 2030 74.688