Year	% of internal resources
1975	22.693531283138917
1976	25.417302933828207
1977	28.141074584729587
1978	30.86484623541888
1979	33.58861788610817
1980	36.312389537009544
1981	39.03616118769884
1982	41.759932838388124
1983	44.48370448928951
1984	47.207476139978795
1985	49.93124779066809
1986	52.655019441569465
1987	55.37879109225875
1988	54.254892509437965
1989	53.13099392661719
1990	52.00709534358431
1991	50.8811737573701
1992	49.75676942354189
1993	48.63236508992577
1994	47.50796075609756
1995	46.38355642226936
1996	45.25915208865324
1997	44.13474775482503
1998	43.01590668080594
1999	43.01590668080594
2000	43.01590668080594
2001	43.01590668080594
2002	43.01590668080594
2003	43.01590668080594
2004	43.01590668080594
2005	43.01590668080594
2006	43.01590668080594
2007	43.01590668080594
2008	43.01590668080594
2009	43.01590668080594
2010	43.01590668080594
2011	43.01590668080594
2012	43.01590668080594
2013	43.01590668080594
2014	43.01590668080594
2015	43.01590668080594
2016	43.01590668080594
2017	43.01590668080594
2018	43.01590668080594
2019	43.01590668080594
2020	43.01590668080594