-81.79% is the change from 280 to 51
Calculation steps:
[( 51 - 280 ) ÷ 280] x 100 = -81.79%
Formula
Percentage change = [(51 - 280) / 280] x 100
Subtract the new number by the original number
51 - 280 = -229
-229 ÷ 280 = -0.8178571428571428
-0.8178571428571428 x 100 = -81.79%