ZONE 1
Co Down, area of South and South East Co Antrim and eastern Co Armagh
ZONE 2
Includes the whole of Co Fermanagh, approximately the western half of Co Armagh and approximately the southern half of Co Tyrone.
ZONE 3
Includes majority of co Derry/Londonderry and approximately the northern half of Co Tyrone.
ZONE 4
Includes the majority of Co Antrim and a small area to the north east of Co Derry/Londonderry.