Year maximum value in 2004 = 100 2006 11.7983028619 2007 12.8256055786 2008 13.743541823 2009 12.6271862421 2010 12.0749195214 2011 13.1081636744 2012 16.9106501061 2013 18.7806073638 2014 20.8151656883 2015 19.0704124694 2016 25.973572254 2017 25.2631975236 2018 23.5562742961 2019 29.7547292976 2020 24.8303027392 2021 24.011206608