Year % of internal resources 1994 18.153167349511502 1995 18.36038449416956 1996 18.567601638827608 1997 18.77481878348566 1998 18.982035928143713 1999 19.189253072801765 2000 19.396470217459814 2001 19.10384494169556 2002 18.811219665931294 2003 18.51859439016703 2004 18.225969114402773 2005 17.93334383863851 2006 17.64071856287425 2007 17.505025037661518 2008 17.369331512448788 2009 17.233637987236055 2010 17.09794446202332 2011 16.96225093665301 2012 16.826557411440277 2013 16.690863886227543 2014 16.555170361014813 2015 16.41947683580208 2016 13.786637251812166 2017 12.587456665616138 2018 15.401827923101163 2019 16.706586826347305 2020 16.706586826347305