Year maximum value in 2004 = 100 2006 13.0825674702 2007 12.8505075331 2008 13.8481232602 2009 14.3914367926 2010 13.4068784555 2011 14.6265419387 2012 13.5536038407 2013 14.5422240174 2014 15.2884374201 2015 18.7720165257 2016 15.5326793267 2017 15.9432625966 2018 17.3444249121 2019 17.3822270863 2020 16.7250428433 2021 16.4831343637