Figures for the number of occasions in 2006 and 2007 information has been withheld in full using section 12 of the Freedom of Information Act because the cost of providing a response would exceed the cost limit have been published in the 2006 and 2007 annual reports on the operation of the FOI Act in Central Government.
2006
http://www.justice.gov.uk/docs/foi-annual-report-central-gov-2006.pdf
2007
http://www.justice.gov.uk/docs/foi-report-2007-final-web.pdf
In the period January-June 2008 the number of request received and refused on grounds of cost was 124.