Year maximum value in 2004 = 100 2006 13.4430150297 2007 13.572184053 2008 13.7025685992 2009 16.0825996528 2010 15.3336111726 2011 15.4927237614 2012 19.2942747925 2013 19.4019161092 2014 22.3164471107 2015 20.7492970884 2016 26.6666499601 2017 25.08878115 2018 23.4332774455 2019 30.4678320108 2020 23.6039730155 2021 23.3879860863