-74.2% is the change from 500 to 129
Calculation steps:
[( 129 - 500 ) ÷ 500] x 100 = -74.2%
Formula
Percentage change = [(129 - 500) / 500] x 100
Subtract the new number by the original number
129 - 500 = -371
-371 ÷ 500 = -0.742
-0.742 x 100 = -74.2%