Year % of tax revenue 2005 14.823529411764705 2006 14.533687774929586 2007 11.89185917714902 2008 12.211941559179678 2009 10.571086804787837 2010 13.321728828390524 2011 12.857321949553535 2012 11.79294552840978 2013 10.986269067857531 2014 10.18156339465332 2015 9.2025029569386 2016 8.408972565216322 2017 10.120126713414864 2018 10.851182499389814 2019 10.233543508885552 2020 8.759532110700146 2021 9.139514509363515 2022 9.503653642721805