... was spoken in the area in which Brookton, Northan and Toodyay stand today (Douglas 1968:3) Lower Blackwood River; chiefly on the hills in country between the Blackwood and Warren rivers; east to Gardner River and Broke Inlet; on Scott River; inland to Manjimup and Bridgetown (Tindale 1974). (WA handbook follows Tindale. Douglas' location is different from Tindale or a map in Gerritsen 1998.)
Speaker numbers were measured differently across the censuses and various other sources listed in AUSTLANG. You are encouraged to refer to the sources.
Speaker numbers for ‘NILS 2004’ and ‘2005 estimate’ come from 'Table F.3: Numbers of speakers of Australian Indigenous languages (various surveys)' in 'Appendix F NILS endangerment and absolute number results' in McConvell, Marmion and McNicol 2005, pages 198-230 (PDF, 2.5MB).
Douglas, Wilfrid. 1968. The Aboriginal languages of the south-west of Australia. Canberra: AIAS.