-75.94% is the change from 320 to 77
Calculation steps:
[( 77 - 320 ) ÷ 320] x 100 = -75.94%
Formula
Percentage change = [(77 - 320) / 320] x 100
Subtract the new number by the original number
77 - 320 = -243
-243 ÷ 320 = -0.759375
-0.759375 x 100 = -75.94%