Year	% of internal resources
1975	278.85090909090906
1976	279.1045454545455
1977	279.3581818181818
1978	279.6118181818182
1979	279.8654545454545
1980	280.11909090909086
1981	280.37272727272733
1982	280.62636363636364
1983	280.88
1984	281.1336363636364
1985	281.3872727272727
1986	281.64090909090913
1987	281.89454545454544
1988	282.1481818181818
1989	282.4018181818182
1990	282.6554545454545
1991	282.90909090909093
1992	286.3353535352727
1993	289.76161616163637
1994	293.18787878781814
1995	296.61414141418186
1996	300.0404040403636
1997	303.4666666667273
1998	306.8929292929091
1999	310.3191919192727
2000	313.74545454545455
2001	316.065
2002	318.3845454545455
2003	320.7040909090909
2004	323.0236363636364
2005	325.34318181818185
2006	328.0772727272727
2007	330.8113636363636
2008	333.6363636363636
2009	332.8909090909091
2010	336.8727272727273
2011	326.3272727272727
2012	341.59999999999997
2013	333.6363636363636
2014	354.3090909090909
2015	358
2016	363.21818181818185
2017	363.58181818181816
2018	350.43636363636364
2019	322.01818181818186
2020	344.7090909090909