Hi Lois,
It's not a census - the classification on FamilySearch is confused. It's most definitely a Household Examination Book, which normally spans a period of time which varies depending on how quickly the priests ran out of space in the book, normally. Perhaps FamilySearch isn't set up to classify this particular type of record accurately.
The correct source reference for the particular volume the information comes from should be: Gnarp (X) AIIa:2a (1909-1912), p. 268.