Year % of tax revenue 2013 0.9617586443782917 2014 1.4703206139508014 2015 2.16479489332743 2016 5.741271756117956 2017 4.779918624359167 2018 5.09987986572429 2019 3.0114025302380423 2020 4.883389629117139 2021 2.679172894679748 2022 3.4922101045423175