Year	maximum value in 2004 = 100
2006	20.5107860009
2007	21.7231492078
2008	20.639482963
2009	19.3410329288
2010	19.9892405978
2011	18.5756796848
2012	20.6624350588
2013	21.2215469283
2014	20.7696747595
2015	20.8578397533
2016	30.2208473271
2017	30.3153567819
2018	29.128876166
2019	29.0626833816
2020	28.8712002497
2021	30.5023208602