Year Percent 1990 56.744 1991 57.873 1992 59.291 1993 60.495 1994 61.268 1995 62.606 1996 63.468 1997 64.436 1998 65.378 1999 66.138 2000 66.742 2001 67.51 2002 68.5 2003 69.504 2004 70.286 2005 70.964 2006 71.854 2007 72.43 2008 72.992 2009 73.323 2010 73.614 2011 73.981 2012 74.485 2013 75.014 2014 75.453 2015 75.827 2016 76.305 2017 76.594 2018 76.885 2019 77.166 2020 77.435 2021 77.693 2022 77.939 2023 78.176 2024 78.41 2025 78.645 2026 78.882 2027 79.117 2028 79.353 2029 79.589 2030 79.825