Year	% of internal resources
1987	2.5294117647058822
1988	2.6934563174208144
1989	2.857709711085973
1990	3.0205012182352937
1991	3.1846501914479637
1992	3.348799164615385
1993	3.5129481378280545
1994	3.677097111040724
1995	3.841246084253394
1996	4.005395057420815
1997	4.169857292036199
1998	4.333693003846154
1999	4.497946397511312
2000	4.661990950226245
2001	4.7767420814479635
2002	4.891493212669683
2003	5.006244343891403
2004	5.120995475113122
2005	5.235746606334842
2006	5.3172850678733035
2007	5.398823529411765
2008	5.480361990950225
2009	5.561900452488688
2010	5.643438914027149
2011	5.643438914027149
2012	5.643438914027149
2013	5.643438914027149
2014	5.643438914027149
2015	5.643438914027149
2016	5.643438914027149
2017	5.643438914027149
2018	5.643438914027149
2019	5.643438914027149
2020	5.643438914027149