Year Percent 1990 46.23 1991 48.188 1992 49.293 1993 50.269 1994 51.232 1995 51.826 1996 52.087 1997 52.867 1998 53.763 1999 55.898 2000 56.502 2001 54.315 2002 55.209 2003 55.568 2004 57.431 2005 59.267 2006 59.424 2007 60.426 2008 60.754 2009 60.822 2010 61.678 2011 60.892 2012 61.109 2013 62.114 2014 62.885 2015 62.996 2016 62.918 2017 63.154 2018 63.369 2019 63.572 2020 63.765 2021 63.926 2022 64.068 2023 64.205 2024 64.361 2025 64.55 2026 64.75 2027 64.983 2028 65.243 2029 65.519 2030 65.8