Year	% (cumulative)
1971	13.7424697875977
1981	29.3434391021729
1990	23.759880065918
2000	41.8400001525879
2001	43.7599983215332
2002	43.8800010681152
2003	44.3899993896484
2004	44.4599990844727
2005	48.0999984741211
2006	49.8400001525879
2007	50.8600006103516
2008	52.5900001525879
2009	53.7099990844727
2010	55.0800018310547
2011	56.7999992370605
2012	56.7099990844727
2013	58.7799987792969
2014	60.2999992370605
2015	69.5971527099609
2016	74.4302291870117
2017	70.8813171386719