-72.5% is the change from 280 to 77
Calculation steps:
[( 77 - 280 ) ÷ 280] x 100 = -72.5%
Formula
Percentage change = [(77 - 280) / 280] x 100
Subtract the new number by the original number
77 - 280 = -203
-203 ÷ 280 = -0.725
-0.725 x 100 = -72.5%
Example