Year	% (cumulative)
1971	2.61450004577637
1981	7.02726984024048
1990	11.776909828186
2001	23.1873798370361
2005	17.4988689422607
2006	13.0198202133179
2007	13.9621200561523
2008	14.6842603683472
2009	15.9215002059937
2010	23.5846309661865
2011	24.8644104003906
2012	26.266321182251
2015	29.7775592803955
2016	34.2898902893066
2017	30.211612701416