New tax credits were introduced in April 2003, and are currently in their 5th year of operation.
Statistics of finalised annual tax credits awards for 2003-04, 2004-05 and 2005-06 and provisional estimates as at April 2007 by constituency are available on the HMRC website at:
http://www.hmrc.gov.uk/stats/personal-tax-credits/cwtc-geog-stats.htm