Concept: Quarterly average/mean in the primaryObservation vocabulary

Concept URI	http://dd.eionet.europa.eu/vocabulary/aq/primaryObservation/quarter
Preferred label	Quarterly average/mean
Definition	The average or mean derived from a sample(s) taken over a 3-month period. The duration will be defined by the startTime & endTime components of the data array.
Notation	quarter
Status	Valid
Status Modified	2013-12-31
Accepted Date	2013-12-31
Not Accepted Date