Year % 1990 44.3671766342142 1991 45 1992 45.4900260190807 1993 45.9219858156028 1994 46.2197282929711 1995 46.4456166792263 1996 46.5670348711284 1997 46.6590519703027 1998 46.6926729986431 1999 46.7210591133005 2000 46.7403628117914 2001 46.7802022352315 2002 46.8238874096615 2003 46.8650502081803 2004 46.9295101553166 2005 47.043611143764 2006 47.2157502329916 2007 47.4503426646533 2008 47.7243627051566 2009 48.0464625131996 2010 48.3828775267539 2011 48.5956416464891 2012 48.6669958035053 2013 48.8732217046456 2014 49.1030240902101 2015 49.2770613520907 2016 49.3527080581242 2017 49.4133333333333 2018 49.5503959200107 2019 49.6175010065763 2020 49.5862253069941 2021 49.4313673631315 2022 49.2695016957996