Vehicle excise duty (VED) is levied on vehicles, not individuals. As vehicles can be owned by more than one person or by a company or organisation, figures for the number of people liable to pay VED are not available. Statistics showing the number of licensed vehicles for each year from 1995-2005 are available on the Department for Transport website at the following address:
http://www.dft.gov.uk/stellent/groups/dft_transstats/documents/downloadable/dft_transstats_611686.xls#‘ Table 1’!A1