Year maximum value in 2004 = 100 2006 8.8441322738 2007 10.4895558112 2008 10.7950849447 2009 10.496836968 2010 9.8646879078 2011 11.332944415 2012 10.2577789151 2013 10.36175216 2014 10.287879848 2015 11.0139898985 2016 9.5864649854 2017 8.4665853397 2018 10.1833826808 2019 10.8401757189 2020 10.45123753 2021 10.8676079537