Year maximum value in 2004 = 100 2006 8.6137906628 2007 4.6637631704 2008 5.899139465 2009 7.0143100333 2010 7.1177081256 2011 6.9623513394 2012 6.1977899793 2013 7.0593239134 2014 6.6965728574 2015 7.4295323796 2016 7.8635012954 2017 12.6053893325 2018 7.1935137614 2019 7.5391936644 2020 6.1667139652 2021 6.0457500488