NPS Calculation

Hello,

Hoping anyone could help me calculate the NPS of our organization using the this column (Rating 1-10). For some reason someone rated a -1 but hoping it could be added to the computation.

Calculating NPS is excel is fairly easy but I'm having a hard time on DAX. Not the expert yet on PowerBI 

Excel

Promoter =9-10

Passives = 7-8

Detractor = <=6

NPS (Promoter - Detractor) / Total Survey *100