Year maximum value in 2004 = 100 2011 9.11426213 2012 9.9485028958 2013 9.7166537111 2014 8.8474098584 2015 9.7172986309 2016 10.6802128651 2017 8.5066278749 2018 8.2305880234 2019 8.3820318527 2020 9.5437176077 2021 6.5930880184