Year	% of internal resources
1980	0.36697247706422015
1981	0.40978593272171254
1982	0.4525993883792049
1983	0.4954128440366972
1984	0.5382262996941896
1985	0.581039755351682
1986	0.6081258191437309
1987	0.6352118829051988
1988	0.6622979466972477
1989	0.6893840104892965
1990	0.7164700742813456
1991	0.7435561380428135
1992	0.7706422018348624
1993	0.7977282656269112
1994	0.8248143293883792
1995	0.8519003931804282
1996	0.878986456972477
1997	0.9060725207645259
1998	0.9331585845259939
1999	0.9602446483180429
2000	1.0374836173088686
2001	1.1147225862691132
2002	1.1919615552599387
2003	1.2692005242507645
2004	1.3464394932415902
2005	1.4236784622018348
2006	1.5009174311926605
2007	1.5233180428134556
2008	1.5457186544342507
2009	1.5681192660550458
2010	1.590519877675841
2011	1.9478593272171256
2012	2.30519877675841
2013	2.662538226299694
2014	3.0198776758409784
2015	3.0198776758409784
2016	3.0198776758409784
2017	3.0198776758409784
2018	3.0198776758409784
2019	3.0198776758409784
2020	3.0198776758409784