1. Hamilton Institute, Mathematics and Statistics, Maynooth University, County Kildare, W23 F2K8 Maynooth, Ireland
2. Department of Statistics, Center of Natural and Exact Sciences, Federal University of Pernambuco, Recife 50.740-540, PE, Brazil
3. Statistics Department, Institute of Mathematics and Statistics, Federal University of Bahia, Salvador 40.170-110, BA, Brazil
4. Statistics Department, Exact Sciences Sector, Federal University of Paraná, Curitiba 81.531-980, PR, Brazil