Year maximum value in 2004 = 100 2006 37.638986124 2007 38.2991614367 2008 34.7539941297 2009 40.9408555545 2010 43.2725979788 2011 39.2502362103 2012 39.4913756321 2013 43.2529554648 2014 41.0570890273 2015 43.9635213318 2016 43.7158383649 2017 43.7984357683 2018 44.7202260322 2019 51.1957057784 2020 63.4028058295 2021 68.9471968408