Year	% of internal resources
1991	22.627368421052633
1992	26.50042606526316
1993	30.373483709210525
1994	34.24654135342105
1995	33.821353383421055
1996	32.31458646605263
1997	30.807819548947368
1998	29.301052631578944
1999	28.68693035210526
2000	28.064913336052633
2001	27.45079105657895
2002	26.836668777105267
2003	26.222546497894733
2004	25.60842421842105
2005	24.99430193894737
2006	23.838939058157894
2007	24.06842105263158
2008	23.892865497105266
2009	23.71730994157895
2010	23.54175438605263
2011	23.366198830526315
2012	23.190643274736843
2013	23.015087719210527
2014	22.83953216368421
2015	22.663976608157895
2016	22.48842105263158
2017	16.214394736842106
2018	16.130342105263157
2019	16.130342105263157
2020	16.130342105263157