Year % of internal resources 1995 28.11901681759379 1996 26.416558861578267 1997 24.71410090556274 1998 23.011642949547216 1999 21.309184993531694 2000 19.60672703751617 2001 17.904269081500644 2002 17.24514877102199 2003 16.586028460543336 2004 15.926908150064682 2005 15.267787839586028 2006 14.956015523932727 2007 14.644243208279429 2008 11.996119016817593 2009 9.347994825355757 2010 6.69987063389392 2011 4.051746442432083 2012 3.4721862871927556 2013 2.892626131953428 2014 2.3130659767141006 2015 2.469598965071151 2016 1.9915912031047862 2017 1.6752910737386804 2018 1.6454721862871928 2019 1.6454721862871928 2020 1.6454721862871928