Year % 1999 0 2000 4.81 2001 6.7 2002 6.84 2003 4.89 2004 4.88 2005 3.74 2006 3.9 2007 4.89 2008 4.89 2009 4.89 2010 4.91 2011 4.91 2013 4.91 2015 4.88 2017 5.04 2018 4.97 2019 5.02 2020 5.02 2021 4.96