gpz represents a geopolitical zone which, in the Nigerian
context, is a national subdivision that groups contiguous states that bear
certain socio-cultural and political similarities. Historically, they arise
from sub-national administrative divisions known as 'Regions' that existed
at the time of the country's independence. There are at present 6 such
zones - North-Central, North-East, North-West, South-East,South-South and
South-West.