How to calculate number of days to fill a volume via API call, which been shown in OCUM

[jnpr]

Is the growth(slope) to be calculated with the reference of past 90 days or more?
May i know how exactly it works?

[gaurav_verma]

I dont think it is possible only with API. OCUM leverage functionality of database. Where OCUM can multiply daily growth rate, do the math and subtract from available space in volume. If you really need to achieve it by yourself then you have to build your DB where using API you can push data and do math. 

Best option is either use OCUM API or query to OCUM DB's ocum_report table.