Year	% of internal resources
1970	17.782519783053257
1971	18.67164577220592
1972	19.560771761358588
1973	20.449897750511244
1974	21.339023739663908
1975	22.228149728816575
1976	23.11727571796924
1977	24.006401707121903
1978	24.89552769627456
1979	25.784653685427223
1980	26.67377967457989
1981	27.56290566373255
1982	28.452031652885218
1983	29.341157642037874
1984	30.23028363119054
1985	31.119409620343202
1986	32.89766159864853
1987	34.67591357695385
1988	36.45416555525918
1989	38.23241753356451
1990	39.44162887881213
1991	40.50599351738241
1992	41.5703581559527
1993	42.634722794522986
1994	43.69908743309327
1995	44.76345207166356
1996	45.82781671112296
1997	46.89218134969326
1998	47.956545988263535
1999	49.020910626833825
2000	50.08527526540411
2001	51.6330280670401
2002	53.735272166800044
2003	55.30581892504668
2004	56.87636568418245
2005	58.4469124424291
2006	60.01745920156486
2007	61.58800595981151
2008	63.15855271805815
2009	64.72909947719391
2010	66.29964623544056
2011	67.87019299457633
2012	69.3518271539077
2013	72.77199845914465
2014	76.19216976349247
2015	79.61234106872944
2016	82.06632879879079
2017	87.15212945674402
2018	87.15212945674402
2019	87.15212945674402
2020	87.15212945674402