Year maximum value in 2004 = 100 2006 5.4067847844 2007 6.4936339077 2008 7.8297216493 2009 6.2989254688 2010 6.3016266113 2011 5.997707419 2012 7.7885046764 2013 8.4854155987 2014 7.529065893 2015 7.3885077569 2016 6.2274920672 2017 6.6449165255 2018 6.3827547211 2019 5.6254251367 2020 5.6217920814 2021 5.6052838891