Local Government Finance Bill

I wonder whether the hon. Lady knows the answer to a question that is confusing me—I apologise to the Committee for my ignorance about this matter. Once the baseline for a budget is set at the beginning of the year, is that set in concrete, so that it is paid via business rates through the Government and essentially becomes a central Government payment, or does it represent locally collected business rates that are not then given to the Government? In short, is that baseline interruptible or is the next year interruptible, when a council's business rates have gone down?