-74.4% is the change from 500 to 128
Calculation steps:
[( 128 - 500 ) ÷ 500] x 100 = -74.4%
Formula
Percentage change = [(128 - 500) / 500] x 100
Subtract the new number by the original number
128 - 500 = -372
-372 ÷ 500 = -0.744
-0.744 x 100 = -74.4%