Year	maximum value in 2004 = 100
2006	20.8182492765
2007	22.5699168546
2008	21.5131631924
2009	18.8366207986
2010	18.2399058155
2011	21.3399624857
2012	22.1899211158
2013	23.0335834709
2014	24.7451726965
2015	25.107167784
2016	24.6783308234
2017	26.8011774636
2018	26.153802048
2019	26.0729770591
2020	26.0910481279
2021	26.7003432494