Year maximum value in 2004 = 100 2008 3.3819078579 2009 3.5526469381 2010 3.4628926147 2011 3.8942501171 2012 4.1090841527 2013 4.5579123703 2014 3.9560375928 2015 3.7626010182 2016 5.219392813 2017 3.1785110022 2018 3.0720506427 2019 5.4343356051 2020 5.4365316794 2021 4.4277308052