Year	% (cumulative)
1971	38.3216514587402
1981	50.7143898010254
1991	52.065128326416
2005	74.2021636962891
2007	73.5906066894531
2008	72.4694595336914
2009	75.810188293457
2010	76.5560989379883
2011	76.4276962280273
2012	76.9751129150391
2013	77.3063583374023
2014	78.4265899658203
2015	79.0129013061523
2016	79.3689804077148
2017	79.6625823974609
2018	80.0708312988281
2019	80.6740493774414
2020	80.9440231323242
2021	81.4542465209961