1. Niloofar Moosavi is Ph.D. Student, Department of Statistics, USBE, Umeå University, 901 87, Umeå, Sweden
2. Jenny Häggström is Associate Professor, Department of Statistics, USBE, Umeå University, 901 87, Umeå, Sweden
3. Xavier de Luna is Professor, Department of Statistics, USBE, Umeå University, 901 87, Umeå, Sweden