Year maximum value in 2004 = 100 2006 9.4433602105 2007 9.2734392264 2008 9.1119733352 2009 9.5193092812 2010 10.2784138574 2011 9.8148083399 2012 10.2647118905 2013 10.8371812831 2014 7.5872356645 2015 8.1582243122 2016 7.550631019 2017 7.6696157466 2018 7.4756725652 2019 7.1847949964 2020 6.1457124177 2021 5.6244635779