Given the task definition and input, reply with output. This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

Between 1836 and 1842 Victorian Aboriginal groups were largely dispossessed[by whom?] of their land. By January 1844, there were said to be 675 Aborigines resident in squalid camps in Melbourne. The British Colonial Office appointed five Aboriginal Protectors for the Aborigines of Victoria, in 1839, however their work was nullified by a land policy that favoured squatters to take possession of Aboriginal lands. By 1845, fewer than 240 wealthy Europeans held all the pastoral licences then issued in Victoria and became a powerful political and economic force in Victoria for generations to come.
Between what year's did Victorian aboriginal groups dispossessed?