Year maximum value in 2004 = 100 2006 9.3564180781 2007 8.4642480704 2008 7.9818971707 2009 5.9467108177 2010 5.6041565417 2011 5.5102957227 2012 5.4990272739 2013 6.1125918868 2014 6.132319711 2015 6.2928606759 2016 6.8810848922 2017 6.9101058795 2018 7.0191152074 2019 7.3201439877 2020 7.5270874278 2021 8.0908498803