Year	% of internal resources
1990	29.66741071428572
1991	29.485714285714288
1992	29.304017857142856
1993	29.12232142857143
1994	28.940625000000004
1995	28.758928571428573
1996	28.70982142857143
1997	28.66071428571429
1998	28.611607142857142
1999	28.5625
2000	28.421875000000004
2001	28.896978021875004
2002	29.372081043973218
2003	29.847184065848214
2004	30.32228708794643
2005	30.797390109821432
2006	31.272493131919642
2007	31.74759615379465
2008	32.22269917589286
2009	32.69780219776786
2010	33.172905219866074
2011	33.648008241741074
2012	34.12311126383929
2013	31.88839285714286
2014	36.770089285714285
2015	41.651785714285715
2016	42.52232142857143
2017	43.25892857142858
2018	43.83928571428572
2019	44.642857142857146
2020	45.33482142857143