Estimates of the average liability of properties in London in 2009-10 and 2010-11 are respectively £20,600 and £22,600 (values rounded to the nearest hundred pounds). For 2010-11, the estimate is before transitional arrangements, inflation and other reliefs. For 2009-10, the estimate is before transitional arrangements and other reliefs but after inflation.
Estimates of the total number of properties and their total liability for business rates broken down by region, for financial years 2009-10 and 2010-11, i.e. before and after revaluation, have been published in table 1 of the transitional arrangements for the non-domestic rating revaluation consultation paper published on 8 July 2009 at:
http://www.communities.gov.uk/publications/localgovernment/nndrrevaluation2010