Year	% (cumulative)
1970	2.94565010070801
1976	5.43953990936279
1980	5.84222984313965
2004	7.53762006759644
2006	8.10297966003418
2007	8.42728042602539
2008	9.09022998809814
2009	9.50755023956299
2010	9.97198963165283
2011	10.104229927063
2012	10.5189399719238
2013	11.1046895980835
2014	11.4194803237915
2015	11.8610897064209
2016	13.56130027771
2017	13.6858901977539
2018	14.5473403930664