Year	% of internal resources
1992	47.18693284936479
1993	45.439201451905625
1994	43.687840290381125
1995	41.936479128856625
1996	40.185117967332125
1997	38.433756805807626
1998	36.68239564428312
1999	34.93103448275862
2000	33.17604355716878
2001	32.018511796733215
2002	30.85735027223231
2003	29.6961887477314
2004	28.535027223230486
2005	27.368421052631582
2006	27.287840290381126
2007	27.201451905626133
2008	27.11578947368421
2009	27.029764065335755
2010	26.950998185117964
2011	25.15834845735027
2012	23.365698729582576
2013	21.57304900181488
2014	19.780399274047188
2015	16.531760435571687
2016	16.923774954627948
2017	19.42831215970962
2018	19.42831215970962
2019	19.230490018148817
2020	17.166969147005442