The Department for Transport is not involved in the management of the Air Travel Organiser's Licence (ATOL) scheme and therefore does not collect any datasets in this regard.
The ATOL scheme is managed by the Civil Aviation Authority (CAA) and protects those consumers who book an ATOL-protected holiday from losing their money or being stranded abroad as a result of travel company insolvency. I would refer the hon. Member to the CAA's website for more details:
http://www.caa.co.uk/default.aspx?catid=27