Turns is the average monthly sales over the last 3 months divided by the current stock. The rating is based on the number of turns according to the following formula:
Turns >= 6: Rating = 1
Turns < 6 and Turns >= 5: Rating = 2
Turns < 5 and Turns >= 4: Rating = 3
Turns < 4 and Turns >= 3: Rating = 4
Turns < 3 and Turns >= 2: Rating = 5
Turns < 2 and Turns >= 1: Rating = A
Turns < 1 and Turns >= 0.5: Rating = B
Turns < 0.5 and Turns >= 0.42: Rating = C
Turns < 0.42 and Turns >= 0.33: Rating = D
Turns < 0.33 and Turns >= 0.25: Rating = E
Turns < 0.25 and Turns >= 0.17: Rating = F
Turns < 0.17 and Turns >= 0.08: Rating = G
Turns < 0.08: Rating = H
The rating change date is the projected date the rating will change if the average monthly sales stays the same. That's why it's always in the future.