The Protestation Returns of 1641/2 are currently being digitised and made freely accessible on the UK Parliament website.
My understanding is that for each parish the oath was performed by everybody on a single day in February or March of 1641/2. Were only inhabitants of the parish recorded on the return for that parish? How were visitors or travellers handled? Did anyone qualified to take the oath take it, regardless of where their permanent abode was? If someone was away at the time of the Protestation, might they have been added at a later date?
When interpreting these returns it seems important to understand precisely who was qualified to take the oath in a parish.