Year maximum value in 2004 = 100 2006 12.8012636579 2007 12.252566529 2008 12.4112547388 2009 16.0387441143 2010 14.7757952622 2011 13.7653922331 2012 13.4548673918 2013 14.915485345 2014 20.0412759994 2015 26.5258780484 2016 33.1634555371 2017 33.6902673106 2018 33.9240085028 2019 34.6097386822 2020 36.572261736 2021 36.2431858825