Year maximum value in 2004 = 100 2006 19.0829956463 2007 20.2069793125 2008 19.8307799932 2009 20.6304500625 2010 24.2391755783 2011 25.3102630196 2012 25.575157332 2013 25.0495697691 2014 26.0233703523 2015 26.0382126821 2016 27.7471735427 2017 29.7425825386 2018 29.1833504816 2019 31.1902991638 2020 32.2416827587 2021 28.5971618148