Research data are not shared. Data are drawn from a restricted access data source and hence cannot be made publicly available. The data used are administrative Danish data maintained by Statistics Denmark, which is kept in a secure server. The data can, however, be accessed remotely from within Danish universities and research institutions. If a researcher at a university or other research institution outside Denmark wishes to use these data, this may be accomplished by visiting a Danish research institution or by cooperating with researchers or research assistants working in Denmark.