Year maximum value in 2004 = 100 2006 8.1402441345 2007 9.4931578656 2008 8.7440647064 2009 8.1371330395 2010 7.6635518017 2011 7.558767567 2012 7.7836635669 2013 9.029053744 2014 9.6371961532 2015 11.7443999601 2016 11.2942514557 2017 11.3430275512 2018 13.1612489073 2019 12.191119859 2020 13.8044915393 2021 14.6716584186