Year maximum value in 2004 = 100 2006 6.9461184705 2007 7.7826793145 2008 7.8782336086 2009 8.1726126816 2010 10.2890285956 2011 8.0357152172 2012 8.20029859 2013 9.0725092443 2014 9.0868965974 2015 8.9364808418 2016 9.6501960472 2017 10.1757997562 2018 9.5311524942 2019 8.7800919604 2020 8.2148786049 2021 8.9030727497