Year maximum value in 2004 = 100 2006 7.3118016506 2007 6.8538003148 2008 16.5672578526 2009 5.745420503 2010 5.9082024528 2011 5.8534192071 2012 6.7908561715 2013 5.8307952883 2014 10.2351019414 2015 8.3758816598 2016 6.4349677657 2017 6.7995213361 2018 7.3381633083 2019 8.0686695272 2020 7.8370165932 2021 7.7842025801