Year	maximum value in 2004 = 100
2006	17.9220066146
2007	16.4528573139
2008	17.211987737
2009	16.855062679
2010	20.0463216075
2011	17.1290933291
2012	18.5065008985
2013	18.4792889489
2014	19.5943100836
2015	17.7839127102
2016	18.6274405469
2017	17.5844891708
2018	18.3556194905
2019	24.2901417484
2020	24.5505720298
2021	23.9311173473