Year Percent 2000 22.70211 2001 23.17449 2002 23.64688 2003 24.11926 2004 24.59165 2005 25.06403 2006 25.53642 2007 26.0088 2008 26.48119 2009 27.38811 2010 28.31026 2011 29.24764 2012 30.20025 2013 31.16809 2014 32.15117 2015 33.14947 2016 34.16301 2017 35.19178 2018 36.23578 2019 37.29501 2020 38.36947 2021 39.45917 2022 39.45917