Year % 2000 4.80524519320894 2001 4.37018283894464 2002 4.50050687266743 2003 4.48438015806446 2004 4.34507059101073 2005 4.19475263646788 2006 4.03195380634209 2007 4.07968860962045 2008 3.90584151588523 2009 3.79623268009416 2010 3.42964227911815 2011 3.31543482593697 2012 3.20564758576395 2013 3.32723085750071 2014 2.84924963159325 2015 2.80433725925938 2016 2.65789588823686 2017 2.43250679902797 2018 2.51826821906983 2019 2.34615557212403 2020 2.11446422286022