Von Brandenstein says that Padupadu (also Padhupadhu) is a term for respect language used by 'at least a dozen languages or dialects in and beyond the Pilbara' (1982:33). He explains that these respect languages differ from ordinary speech mostly in the lexicon and provides data for Padupadu languages in Pandjima A53, Jindjiparndi W37, Ngarluma W38 and Njijapali A50, each of them distinct.
Von Brandenstein (1968:2) also notes an emerging 'unified respect language for Jindjiparndi, Ngarluma, and to an extend Pandjima, together'.
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).