New Life event - Fast formula - creation of person change values

Hello team,

Based on a customer's requirement, employees will switch benefit plans when they change -contract- category.

So a new life event has to be created for this.

As there are no values for this type (employee's contract)

We created a fast formula.

BUT 

It is not very clear to us what value we should put in "table name/column name/ old value/ new value" while adding the formula in the "create person change" creation of the life event, as there is no value related to employee's "contract type".

Could you please assist?

Thank you in advance,

VT