Year maximum value in 2004 = 100 2006 5.6680563724 2007 5.2209548137 2008 5.2209548137 2009 5.2209548137 2010 5.1288326588 2011 5.4736845866 2012 5.8614980122 2013 5.8614980122 2014 5.8178066536 2015 5.8709454763 2016 5.8387405285 2017 5.8868831879 2018 5.9785818327 2019 5.7285412411 2020 5.7285412411 2021 5.2345400353