Year	% (cumulative)
1970	58.7508888244629
1972	62.2182388305664
1976	67.0817413330078
1981	74.2811584472656
1986	78.5133285522461
1990	83.4132308959961
1991	83.9129028320312
1992	84.8839950561523
1993	85.725456237793
1994	85.5336685180664
1995	86.2181854248047
1996	86.612060546875
1997	87.5628433227539
1998	88.0746383666992
1999	88.4225692749023
2000	88.9504776000977
2001	89.8323593139648
2002	90.1067581176758
2003	90.5712585449219
2004	90.9807739257812
2005	91.3520278930664
2006	91.7312088012695
2007	92.1179122924805
2008	92.5901489257812
2009	92.9185409545898
2010	93.1409301757812
2011	93.4728851318359
2012	93.9972229003906
2013	94.067741394043
2014	94.2132339477539
2015	94.6977996826172
2016	94.680534362793
2017	94.9624786376953
2018	95.420768737793
2019	95.3697814941406
2020	95.7951736450195
2021	96.2860412597656
2022	96.2347412109375
2023	96.529296875