Year	% (cumulative)
1970	1.01813995838165
1976	3.20000004768372
1980	4.13836002349854
2004	8.62889957427979
2006	9.12119960784912
2007	10.1406097412109
2008	10.8358097076416
2009	11.5665798187256
2010	12.5146703720093
2011	12.646089553833
2012	13.2493495941162
2013	13.9930000305176
2014	14.7013502120972
2015	15.0609998703003
2016	16.9192790985107
2017	17.5405597686768
2018	18.2920608520508