First, our formula takes the product of the natural log of the rank position and co-efficient a to produce a score that reflects the relative stream count of a given track at a given time due to chart entry.
Next, to take into account scale of chart by country, we factor incountry-based digital revenue data from IFPI (the International Federation of the Phonographic Industry). This parameter adjusts the relative stream count of a track with respect to the chart's country size.
By taking the sum of all scores for each chart entry and plotting it at different time intervals, we are able to accurately demonstrate the traction of a track over time.
We then divide the score by the max score possible for a track in all countries. This way, any score for a specific chart can be compared globally.