Why do yearly specifications on the charts vary??
The earliest possible starting point is determined by the availability of historical daily data. In order to ensure a certain level of timeliness, historical data is initially limited to thirty years (except, for example under “Indices > Long term”). This can however increase as charts are updated. The end date of the historical data series is determined by the day of the last update. For this reason some charts are labeled “30 years seasonal” and others “24 years seasonal”.
