The CPI was rebased in August 2006, with the base year being changed to 2005 from 2000, and yearon-year figures as far back as January 2006 were revised retroactively. Accordingly, the Bank used  BIS Review 105/2006  3  the 2005-base CPI in the October Outlook Report while it used the 2000-base CPI in the April Outlook Report.
At the time of the April Outlook Report, the Bank estimated that the extent of the negative divergence caused by the rebasing was likely to be slightly less than 0.3 percentage point, approximately the same as that at the previous rebasing of the CPI from the 1995 base to the 2000 base.