Year Percent 1991 23.051 1992 24.26 1993 25.528 1994 26.038 1995 26.015 1996 25.256 1997 24.66 1998 24.919 1999 24.252 2000 23.976 2001 23.518 2002 23.836 2003 23.013 2004 21.525 2005 21.783 2006 21.567 2007 22.347 2008 22.548 2009 23.411 2010 22.919 2011 23.163 2012 24.997 2013 25.374 2014 26.04 2015 25.843 2016 23.926 2017 24.119 2018 24.105 2019 24.114 2020 24.088 2021 24.039 2022 23.948