Year	% of internal resources
1990	18.50189393939394
1991	19.11583333333333
1992	19.729772727272728
1993	20.34371212121212
1994	20.957651515151515
1995	21.571590909090908
1996	22.185530303030305
1997	22.799469696969695
1998	23.41340909090909
1999	24.027348484848485
2000	24.641287878787878
2001	24.616818181818186
2002	24.592348484848486
2003	24.56787878787879
2004	24.543409090909094
2005	24.518939393939394
2006	24.518939393939394
2007	24.518939393939394
2008	24.518939393939394
2009	24.518939393939394
2010	24.518939393939394
2011	24.518939393939394
2012	24.518939393939394
2013	24.518939393939394
2014	24.518939393939394
2015	24.518939393939394
2016	24.518939393939394
2017	24.518939393939394
2018	24.518939393939394
2019	24.518939393939394
2020	24.518939393939394