Year	% of internal resources
1970	7.334482758620689
1971	7.342
1972	7.349517241379309
1973	7.35703448275862
1974	7.3645517241379315
1975	7.372068965517242
1976	7.632137931034483
1977	7.892206896551725
1978	8.152275862068965
1979	8.412344827586207
1980	8.672413793103448
1981	8.829655172413792
1982	8.986896551724136
1983	9.144137931034484
1984	9.301379310344828
1985	9.458620689655172
1986	10.27448275862069
1987	11.090344827586208
1988	11.906206896551724
1989	12.722068965517241
1990	13.537931034482758
1991	13.698275862068964
1992	13.858620689655174
1993	13.714367816034484
1994	13.570114942586207
1995	13.425862068965516
1996	14.200000000000001
1997	14.974137931034484
1998	15.164137931034482
1999	15.354137931034483
2000	15.544137931034482
2001	15.734137931034484
2002	15.924137931034485
2003	16.158333333275863
2004	16.392528735689655
2005	16.626724137931035
2006	16.606206896551726
2007	16.585689655172413
2008	16.72116379310345
2009	16.8575
2010	16.99211206896552
2011	17.129310344827587
2012	17.129310344827587
2013	17.112068965517242
2014	17.09655172413793
2015	17.082758620689653
2016	17.475862068965515
2017	17.47241379310345
2018	17.451724137931034
2019	17.439655172413794
2020	17.451724137931034