Year	% of internal resources
1987	0.4646464646464647
1988	0.480963481010101
1989	0.4972804972727273
1990	0.5135975136363635
1991	0.5299145298989899
1992	0.5462315462626262
1993	0.5625485625252525
1994	0.5788655788888889
1995	0.5951825951515152
1996	0.6114996115151515
1997	0.6278166277777778
1998	0.6441336441414142
1999	0.6604506604040404
2000	0.6767676767676768
2001	0.6676599326262627
2002	0.6585521885858586
2003	0.6494444444444445
2004	0.6403367003030304
2005	0.6312289562626263
2006	0.6221212121212122
2007	0.6221212121212122
2008	0.6221212121212122
2009	0.6221212121212122
2010	0.6221212121212122
2011	0.6221212121212122
2012	0.6221212121212122
2013	0.6221212121212122
2014	0.6221212121212122
2015	0.6221212121212122
2016	0.6221212121212122
2017	0.6221212121212122
2018	0.6221212121212122
2019	0.6221212121212122
2020	0.6221212121212122