Year % of internal resources 1992 13.920484581497798 1993 14.21776274387665 1994 14.515040906211455 1995 14.812319068590307 1996 15.109597230969163 1997 15.406875393348018 1998 15.704153555682817 1999 16.001431718061674 2000 18.502202643171806 2001 18.034875183568282 2002 17.567547723920704 2003 17.10022026431718 2004 17.4176578560793 2005 17.735095447885463 2006 18.052533039647578 2007 18.268557268722468 2008 18.484581497797357 2009 19.88105726872247 2010 20.687224669603523 2011 21.46916299559471 2012 22.251101321585903 2013 22.572687224669604 2014 22.894273127753305 2015 23.66079295154185 2016 26.25991189427313 2017 25.89823127753304 2018 26.91347136563877 2019 27.107303964757712 2020 27.107303964757712