Year maximum value in 2004 = 100 2006 7.9129600473 2007 8.4908860632 2008 8.7136440598 2009 8.6816139911 2010 8.7340618142 2011 6.7032744855 2012 7.5713940766 2013 7.5516753069 2014 7.9719890693 2015 8.1037815521 2016 8.3109902414 2017 8.9309888808 2018 7.7262948209 2019 7.9049228058 2020 9.4057006173 2021 8.0183502598