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 4.83 2018 4.72 2019 4.75 2020 4.74 2021 4.69