HI @billi,
You can add a right-click formula column for cumulative sum.
Right-Click on a column and choose New Formula Column.
Choose Row--Cumulative Sum
JMP New Formula ColumnEdit formula to add by variable using "^" insert
This will calculate the cumulative sum as shown in the image below.
Cumulative Sum with By variable
I have attached a modified version of your data table with the included column formula.
cheers,
Stan