Business Rate Supplements Bill

Has my right hon. Friend reflected, during his consideration leading to the introduction of the Bill, on the fact that the contribution to local government finance from the business rate has systematically declined as a proportion of the total amount of revenue coming in because of clauses in the original council tax legislation? Rises in the business rate are restricted to the rate of RPI inflation, so the contribution as a percentage of total income has declined over the years. Has he calculated what that effect has been, and what effect the business rate proposals may have on the total contribution by businesses to council tax revenue?