Year % 1998 11.833648393194714 1999 11.836673044003632 2000 12.142448512585812 2001 12.412818525778365 2002 13.726589136425202 2003 13.522109820205863 2004 14.367174910127686 2005 15.019809359432003 2006 15.532047778905458 2007 16.422986708365908 2008 17.17573464107812 2009 17.840624763060127 2010 18.0093896713615 2011 18.75233470302577 2012 19.85953816737755 2013 20.70179466574829 2014 21.149975314268357 2015 21.846838354511522 2016 22.235961594413737 2017 22.333996743260357 2018 22.768543604012603 2019 23.093381686310064 2020 24.017226148409893 2021 24.528162511542014 2022 24.968953448989577 2023 25.248561959544404