-79.87% is the change from 636 to 128
Calculation steps:
[( 128 - 636 ) ÷ 636] x 100 = -79.87%
Formula
Percentage change = [(128 - 636) / 636] x 100
Subtract the new number by the original number
128 - 636 = -508
-508 ÷ 636 = -0.7987421383647799
-0.7987421383647799 x 100 = -79.87%