What our poll doesn't reveal is why some schools are not celebrating this Christian festival in the usual ways - or why the majority of schools continue to do so when only about a half of the population profess a belief in God and even fewer go to church.
Though teachers seem a bit more religious than most on average, the persistence of school worship owes as much to their sense of duty - or unwillingness to challenge the status quo - as to personal faith. Agnostics and atheists in the staffroom generally do not opt out of assemblies as they are legally entitled to.
And when Christmas comes around, they seem just as susceptible as the rest of society to the habits we call heritage or tradition: the tribal rituals and symbols that bind social groups together and help individuals define where they belong. Nostalgia may be explainable by social theory or Darwinism. But that doesn't stop it remaining a powerful part of what we feel and who we are.
For some teachers, and in some schools, Christmas retains a deeply religious significance. But for others, following the 2,000-year-old script which had the admirable foresight to include a part for every child in a class of 30 need not involve any belief at all. You don't have to harbour anti-Catholic feelings to enjoy a few fireworks on November 5. Or not in England and Wales, anyway.
But just as Bonfire Night may carry different connotations in Ulster, so there are schools which serve communities where the Christian symbols and rituals are not so widely shared. These schools must find other common values to celebrate in the season of peace and goodwill. Teachers'
professional duty requires it. So does their Christian duty to love thy neighbour - even if it challenges tribal loyalties.