The Oxford University Press originally held a monopoly on publishing almanacs. The almanacs traditionally included engravings and information about Oxford University, including the Heads of Colleges and a university calendar. No almanack appeared in 1675, but it has been published annually since 1676.
Paul Luna & Martyn Ould, 'The Printed Page', chapter 17 in Ian Gadd (editor), The History of Oxford University Press. Volume I: Beginnings to 1780 (Oxford University Press, 2013), pages 520-527 (online with subscription)