Year % of internal resources 2005 1.8345588235294117 2006 2.072478991596639 2007 2.3103991596638656 2008 2.5483193277310927 2009 2.786239495798319 2010 3.024159663865546 2011 3.262079831932773 2012 3.4999999999999996 2013 3.7379201680672267 2014 3.9758403361344534 2015 4.1228991596638656 2016 4.023109243697479 2017 3.8445378151260505 2018 3.8445378151260505 2019 3.8602941176470584 2020 3.8602941176470584