Sorting on column which uses offset

[Joshuageorgetho]

I have a dataset as follows, i’m using offset to create a subtotal of PSI, called Total PSI, and then i want to plot date by Total PSI (where not null) on a line chart.

In a table visualisation it outputs like this : 

This is fine but when trying to plot a line chart, the order of Total PSI is completely wrong, and i cannot sort on Total PSI at all because i am using the offset function. 

Could anyone suggest any tips or tricks on how i could somehow sort the y axis ascending?

[Dawid]

Is Total PSI a numeric field?

[Joshuageorgetho]

Total PSI is a sum of PSI grouped by date,  and PSI is a number 

[jhow]

Joshuageorgethomas did you manage getting an answer to this?