Year	% (cumulative)
1971	3.93661999702454
1981	8.63064956665039
1990	12.3072595596313
2001	25.394889831543
2005	15.6508703231812
2006	11.3838300704956
2007	11.9709300994873
2008	12.3504800796509
2009	13.317850112915
2010	19.5927658081055
2011	20.5362396240234
2012	22.0283641815186
2015	24.6002597808838
2016	29.6774101257324
2017	25.3090152740479