Year % 1999 0 2000 4.85 2001 6.79 2002 6.8 2003 4.86 2004 4.88 2005 4.09 2006 4.08 2007 4.88 2008 4.88 2009 4.88 2010 4.91 2011 4.91 2013 4.91 2015 4.91 2017 4.88 2018 4.86 2019 4.87 2020 4.86 2021 4.87