Year maximum value in 2004 = 100 2006 41.1980716222 2007 45.4991119022 2008 42.8236561329 2009 43.9849168375 2010 48.68251257 2011 52.9266210129 2012 49.3304615976 2013 49.973901955 2014 53.7831380584 2015 50.9785568057 2016 52.7322873462 2017 56.7460549562 2018 57.8308861074 2019 64.611879848 2020 70.0021333367 2021 69.4548803031