1. LEMA Research Group, Department of Urban & Environmental Engineering, University of Liège, Liège, Belgium
2. MRC Epidemiology Unit, School of Clinical Medicine, University of Cambridge, Cambridge, UK
3. Faculty of Business Economics, Hasselt University, Diepenbeek, Belgium
4. Department of Mathematics, Education, Econometrics and Statistics (MEES), KULeuven Campus Brussels, Belgium