Year % of internal resources 1990 4.4609665427509295 1991 4.430408921933085 1992 4.399851301115241 1993 4.369293680297398 1994 4.338736059479554 1995 4.30817843866171 1996 4.812936802973978 1997 5.317695167286246 1998 5.822453531598513 1999 6.327211895910781 2000 6.8319702602230485 2001 6.50728624535316 2002 6.182602230483272 2003 5.857918215613383 2004 5.533234200743495 2005 5.208550185873606 2006 4.730185873605949 2007 4.638438661710038 2008 4.546691449814126 2009 4.454944237918216 2010 4.363197026022305 2011 4.271449814126394 2012 4.179702602230483 2013 4.087955390334573 2014 3.9962081784386623 2015 3.420074349442379 2016 4.059479553903346 2017 4.055762081784387 2018 3.5613382899628254 2019 4.204460966542751 2020 2.921933085501859