The Home Office does not hold statistics which are recorded in this way. The Home Office does collate statistics on the number of terrorism arrests and convictions and these are included in a Bulletin published for the first time on 13 May 2009 (Statistics on Terrorism Arrests and Outcomes Great Britain 11 September 2001 to 31 March 2008).
The second issue of the Bulletin was published on 26 November 2009 and, unlike the first edition, includes data on stop/searches under Section 44 of the Terrorism Act 2000. The bulletin is available via the following link:
http://www.homeoffice.gov.uk/rds/pdfs09/hosb1809.pdf
The third issue of this bulletin was published on 25 February 2010 and is available via the following link:
http://www.homeoffice.gov.uk/rds/pdfs10/hosb0410.pdf
In addition to the above bulletins, the Home Office publishes Statistics on Police Powers and Procedures, which includes a force by force breakdown of stop/searches under Section 44. The last edition of that bulletin (covering 2007-08) is available via the following link:
http://www.homeoffice.gov.uk/rds/pdfs09/hosb0709.pdf
The next edition of this bulletin (covering 2008-09) is scheduled to be published before the end of April 2010. Links to the bulletins covering the four years up to 2007-08 are included in the following:
http://www.justice.gov.uk/publications/docs/arrests-recorded-crime-engl-wales-2006-07-b.pdf
http://www.justice.gov.uk/publications/docs/arrests-for-recorded-crime-england-and-wales.pdf
http://www.homeoffice.gov.uk/rds/pdfs05/hosb2105.pdf
http://www.homeoffice.gov.uk/rds/pdfs04/hosb1804.pdf