Year	% (cumulative)
1971	20.115270614624
1981	33.2999992370605
2001	64.4224166870117
2005	68.7590026855469
2006	69.9742279052734
2007	70.8761367797852
2008	71.9095611572266
2009	72.8498764038086
2010	73.8259963989258
2011	74.7727508544922
2012	75.682258605957
2013	77.1464614868164
2014	77.624397277832
2015	78.4582595825195
2016	80.1383743286133
2017	80.9948272705078
2018	81.9430236816406
2019	82.7715072631836
2020	82.1943817138672
2021	82.4618148803711
2022	82.8581771850586