DfE local-authority data for 16–17-year-olds, reporting NEET combined with activity not known, rather than confirmed NEET alone. The 2016 workbook reports an end-2016 measure; see the original DfE technical notes for its reporting conventions. The 2018 and 2019 releases include December–February averages and overlapping historical time-series observations. Do not sum overlapping resources. Original values and suppression symbols preserved.