School year is used as referenceperiod. A school year is defined as 1. July the previous year til 30. June the current year. Re. GIF: Up till 2009/ 2010 only Danish and History are included, thereafter all subjects. Only GSK taken at VUC is included. For documentation follow this link (in danish): http://www.dst.dk/ext/uddannelse/Uddannelsestabeller.