Year Percent 1990 52.198 1991 52.479 1992 52.755 1993 53.008 1994 53.209 1995 53.335 1996 53.345 1997 53.292 1998 53.202 1999 53.114 2000 53.051 2001 53.032 2002 53.038 2003 53.063 2004 53.093 2005 53.122 2006 53.148 2007 53.173 2008 53.152 2009 53.389 2010 54.847 2011 57.818 2012 57.793 2013 58.66 2014 57.975 2015 57.18 2016 57.336 2017 57.736 2018 58.104 2019 58.46 2020 58.813 2021 59.164 2022 59.502 2023 59.831 2024 60.157 2025 60.484 2026 60.819 2027 61.156 2028 61.491 2029 61.82 2030 62.143