Year maximum value in 2004 = 100 2006 1.5528144298 2007 1.7637203359 2008 3.7118681592 2009 3.5242601242 2010 3.8923117814 2011 3.3990677183 2012 3.762082183 2013 5.1262113778 2014 4.81926407 2015 4.7271518222 2016 5.7331076262 2017 4.0096872496 2018 4.324902891 2019 6.1563514982 2020 4.1970724236 2021 4.3676468464