Year % of internal resources 2012 2.0693106194690265 2013 2.1824079646017696 2014 2.4280442477876107 2015 2.8265646017699115 2016 2.5864690265486727 2017 2.15929203539823 2018 2.7023539823008846 2019 2.7771061946902655 2020 2.7752920353982304