The new inflation index has as it's base june 15, 2002. The products used to calculate the index as well as their weightings changed to reflect the current pattern of consumption. The new methodology is used since july 15, 2002. Source releases information on the 24th of each month provided it is a working day. History is stored independently for daily and weekly frequencies. HP values for these frequencies may not match each other. Note that when only one frequency is stored in history, for the other frequencies, history is derived from that of the stored frequency. For example, HP W, HP M, HP Q and HP Y will derive data from HP D when only daily history is stored, HP Q and HP Y will derive data from HP M when only monthly history is stored. As another example, if both daily and monthly are stored, HP W will derive data from HP D, while HP Q and HP Y will derive data from HP M and so on.