The Headline CPI (BCCh splice) uses information from the reference series of each CPI basket published by INE. Specifically, for the period from January 1999 to December 2008, the monthly variations of the CPI basket with base December 1998=100 are used. For January 2009, the monthly variation of the CPI basket with base December 2008=100 is used. For the period from February 2009 to January 2013, the monthly variations of the CPI basket with annual base 2009=100 are used. For the period from February 2013 to January 2018, the monthly variations of the CPI basket with annual base 2013=100 are used. For the period from February 2018 to January 2023, the monthly variations of the CPI basket with annual base 2018=100 are used.
