Year	% of internal resources
1980	83.61818181818182
1981	83.89272727272726
1982	84.16727272727272
1983	84.44181818181818
1984	84.71636363636364
1985	84.9909090909091
1986	82.50727272727272
1987	80.02363636363637
1988	77.54
1989	75.05636363636363
1990	72.57272727272726
1991	72.57272727272726
1992	69.88909090909091
1993	67.20545454545454
1994	64.52181818181818
1995	61.838181818181816
1996	59.15454545454545
1997	63.53181818181818
1998	67.9090909090909
1999	72.28636363636363
2000	76.66363636363637
2001	81.0409090909091
2002	87.0325
2003	93.0240909090909
2004	99.0156818181818
2005	105.00727272727272
2006	102.23818181818183
2007	99.45454545454545
2008	97.36363636363637
2009	103.72727272727273
2010	99.36363636363636
2011	92.63636363636363
2012	97.45454545454547
2013	96.72727272727273
2014	86.27272727272728
2015	76.46363636363635
2016	72.94
2017	71.96545454545455
2018	73.54727272727271
2019	76.39454545454545
2020	75.5090909090909