Year	% (cumulative)
1971	11.7320003509521
1981	27.3580207824707
1990	23.3697204589844
2000	42.7900009155273
2001	44.6399993896484
2002	44.5900001525879
2003	45.3800010681152
2004	45.3899993896484
2005	49.5699996948242
2006	51.939998626709
2007	53.1399993896484
2008	55.25
2009	56.5200004577637
2010	58.25
2011	59.8199996948242
2012	59.6500015258789
2013	61.8800010681152
2014	63.5299987792969
2015	72.0450973510742
2016	76.5098190307617
2017	73.0429382324219