The Department for Transport does not hold data for these specific categories. However, overall average age figures for the national rail fleet are published in the National Rail Trends on the Office of Rail Regulation's website at:
www.rail-reg.gov.uk
The Department for Transport inherited this right to buy rolling stock in 2005 from the Strategic Rail Authority. Since this date, the Department has not exercised the right to buy rolling stock that has been identified by the leasing companies for scrapping or sale.
Rolling stock is normally only offered to the Department when the ROSCO has exhausted all avenues to lease it or does not see a good business case for ownership. As a rule the vehicles they have offered to the Department are usually intended for scrapping such as the Mark 1 slam door stock.