Successive differences ( subtracting previous value) help

[stxphxe]

Hello,

This is my Data from excel

Excel file

this is the data load editor 

Data load editor

So far i have been able to calculate the standard deviation and average for the values in the chart expressions.

How do i calculate the successive differences, that is the differences between each value in each date. For example, 31/07/2017 will be 929-1079 and so on.

[Anil_Babu_Samineni · Accepted solution]

Where you want this? I meant - Script/UI?

[stxphxe]

In the script