Year	% (cumulative)
1970	2.5
1975	4.1
1980	7.42387
1985	11.61723
1988	15.80181
2005	18.09389
2006	18.15597
2007	17.43613
2008	18.12441
2012	20.375
2013	17.62585
2015	20.27724
2017	24.25728
2018	25.56145