Environmental taxes made up 6.3% of tax revenues in the EU in 2014. In the European Union (EU), environmental taxes amounted to €343.6 bn in 2014, compared with €282.0 bn in 2004. However, the share of environment taxes in total revenues from taxes and social contributions has decreased over this 10-year period, from 6.8% in 2004 to 6.3% in 2014. Two of the countries with best resulsts in the share of environmental taxes in the EU are new member states Slvenia and Croatia.
Eurostat report: http://ec.europa.eu/eurostat/documents/2995521/7236510/8-22042016-BP-EN.pdf/b910e804-e410-4b9c-b9ab-1893398e2a2d