Year maximum value in 2004 = 100 2006 7.5269663698 2007 7.3974169012 2008 8.1168771827 2009 10.4811635317 2010 10.1888692597 2011 12.9304214178 2012 10.951455898 2013 11.2601483412 2014 14.1115845615 2015 11.3118621502 2016 13.4030649116 2017 17.2272208354 2018 21.9265579829 2019 14.4792381443 2020 14.1729792237 2021 23.9768820796