Year maximum value in 2004 = 100 2006 4.1580229712 2007 4.0801230107 2008 5.1797512451 2009 4.3164456083 2010 5.7161292434 2011 5.9371625142 2012 7.684272263 2013 8.5769278707 2014 6.3558126198 2015 4.7583975865 2016 5.7495063416 2017 4.5383291927 2018 5.5048161104 2019 5.7922155596 2020 5.1251319869 2021 4.8287397769