Year	% of internal resources
1987	0.14505494505494507
1988	0.14534798534798532
1989	0.14564102564102566
1990	0.14593406593406594
1991	0.14622710622710622
1992	0.14652014652014653
1993	0.17245421245421247
1994	0.19838827838827838
1995	0.22432234432234435
1996	0.25025641025641027
1997	0.2761904761904762
1998	0.3021245421245421
1999	0.32805860805860804
2000	0.35399267399267403
2001	0.36293040293040296
2002	0.3718681318681319
2003	0.3808058608058608
2004	0.38974358974358975
2005	0.3986813186813187
2006	0.3986813186813187
2007	0.3986813186813187
2008	0.3986813186813187
2009	0.3986813186813187
2010	0.3986813186813187
2011	0.3986813186813187
2012	0.3986813186813187
2013	0.3986813186813187
2014	0.3986813186813187
2015	0.3986813186813187
2016	0.3986813186813187
2017	0.3986813186813187
2018	0.3986813186813187
2019	0.3986813186813187
2020	0.3986813186813187