Year	% of internal resources
1975	6.430693069306931
1976	6.426237623762376
1977	6.421782178217822
1978	6.417326732673267
1979	6.412871287128713
1980	6.408415841584159
1981	6.436633663366337
1982	6.464851485148515
1983	6.4930693069306935
1984	6.5212871287128715
1985	6.5495049504950495
1986	6.566831683168317
1987	6.584158415841585
1988	6.601485148514852
1989	6.618811881188119
1990	6.6361386138613865
1991	6.653465346534654
1992	6.670792079207921
1993	6.603019801980198
1994	6.535247524752476
1995	6.467475247524752
1996	6.399702970297031
1997	6.331930693069307
1998	6.312079207920792
1999	6.292227722772278
2000	6.272376237623763
2001	6.252524752475247
2002	6.232673267326732
2003	6.105569306930693
2004	5.978465346534653
2005	5.851361386138614
2006	5.724257425742575
2007	5.597153465346535
2008	5.470049504950496
2009	5.342945544554455
2010	5.215841584158416
2011	5.088737623762377
2012	4.9504950495049505
2013	4.257425742574258
2014	4.217821782178218
2015	4.222566831683168
2016	4.217821782178218
2017	4.217821782178218
2018	4.217821782178218
2019	4.217821782178218
2020	4.217821782178218