Year Percent 1990 35.249 1991 36.049 1992 35.519 1993 36.489 1994 37.814 1995 38.818 1996 37.258 1997 40.537 1998 43.122 1999 43.34 2000 41.805 2001 45.316 2002 45.706 2003 45.069 2004 44.735 2005 48.772 2006 48.51 2007 49.979 2008 50.369 2009 50.852 2010 48.715 2011 51.101 2012 50.796 2013 51.821 2014 54.834 2015 54.513 2016 50.706 2017 51.219 2018 51.733 2019 52.24 2020 52.733 2021 53.212 2022 53.671 2023 54.116 2024 54.564 2025 55.026 2026 55.502 2027 55.991 2028 56.49 2029 56.99 2030 57.487