Year maximum value in 2004 = 100 2006 5.5729997025 2007 5.6659165036 2008 7.9522710711 2009 7.0248183377 2010 6.1515684598 2011 7.8428054642 2012 8.1767324681 2013 9.3867378755 2014 9.3223267994 2015 8.9873789157 2016 8.5371351806 2017 8.9441522747 2018 9.1115800715 2019 8.5124608467 2020 8.9603212309 2021 8.1361458273