Year	% of internal resources
1980	9.296551724137931
1981	9.02344827586207
1982	8.750344827586206
1983	8.477241379310344
1984	8.204137931034483
1985	7.931034482758621
1986	8.002758620689654
1987	8.07448275862069
1988	8.146206896551723
1989	8.217931034482758
1990	8.289655172413793
1991	8.299310344827587
1992	8.30896551724138
1993	8.318620689655171
1994	8.328275862068967
1995	8.337931034482757
1996	8.392269592482759
1997	8.44660815048276
1998	8.50094670848276
1999	8.555285266482757
2000	8.609623824482759
2001	8.663962382413793
2002	8.718300940413794
2003	8.772639498413794
2004	8.826978056413793
2005	8.881316614413793
2006	8.935655172413792
2007	5.8710344827586205
2008	5.756551724137931
2009	5.711034482758621
2010	5.699310344827586
2011	5.3
2012	5.528965517241379
2013	5.276551724137931
2014	5.024137931034483
2015	5.627586206896551
2016	5.806206896551725
2017	5.806206896551725
2018	5.806206896551725
2019	5.806206896551725
2020	5.806206896551725