Year maximum value in 2004 = 100 2006 46.9971737433 2007 45.1184400632 2008 47.4090476722 2009 45.5020786847 2010 46.4001607958 2011 51.7730817488 2012 52.3779286795 2013 54.0266219116 2014 55.6266693031 2015 55.5437539198 2016 56.0794476654 2017 56.928303866 2018 55.2072911093 2019 61.1718524244 2020 68.5087319001 2021 66.6745889083