Year maximum value in 2004 = 100 2006 11.0923192249 2007 12.1658028036 2008 15.3460483553 2009 17.2189557097 2010 18.8660759938 2011 17.6988066185 2012 18.6856655967 2013 20.5761772737 2014 20.6882564869 2015 27.5611269817 2016 30.6908260079 2017 30.6411184797 2018 29.4808182648 2019 33.7426165856 2020 33.5724631086 2021 33.5866263753