Year Number 2013 0.6235960305765916 2014 0.6084946263551606 2015 0.6780383061550502 2016 0.670073280916176 2017 0.5100836519389108 2018 0.38244824599813054 2019 0.3676652003703281 2020 0.31919089584140614 2021 0.387020951723311 2022 0.47832413731020945 2023 0.5229894080049455