Aghadowey, that is fantastic information and a wonderful resource! Extremely helpful, so too is the article, Sinann
Hallmark, the digitized image of Griffiths clearly shows the heading to be "occupiers" whilst the Griffiths Survey Maps & Plans refer to "60 occupants." Clearly the occupiers are heads of household; otherwise the rest of the family, lodgers, live-in servants etc would be included. I know that this is not a census and it was for tax purposes. Ian Maxwell's Tracing Your Northern Irish Ancestors states: " The original purpose was, and remains, the assessment of every building and every piece of land and estimating its financial value." Maxwell also points out that the occupier was the householder or leaseholder. I was confused because the digitized image shows 25 pieces of property represented by 25 names in the occupiers column, and I couldn't reconcile this 25 occupiers with 60 occupants. That's why I asked the question about the meaning of the term "occupant." Aghadowey's chart shows that in 1861 Drumhirk had a total population of 170 and 29 inhabited houses. Those houses may have contained more than one household, but the tax was levied on the property, not on each household within it, so 60 occupants still does not make sense to me. Sorry...