Year	% (cumulative)
1972	40.6413383483887
1981	56.9006996154785
2000	63.5800018310547
2001	63.9300003051758
2002	66.1699981689453
2003	64.1100006103516
2004	66.7600021362305
2005	66.9499969482422
2006	68.8499984741211
2007	71.4000015258789
2008	71.75
2009	72.1399993896484
2010	72.3000030517578
2011	72.1900024414062
2012	73.6699981689453
2013	73.6399993896484
2014	74.6500015258789
2015	75.4599990844727
2016	75.8000030517578
2017	76.1100006103516
2018	76.9199981689453
2019	77.3000030517578
2020	78.7399978637695
2021	78.6800003051758
2022	80.3000030517578