-8.79% is the change from 307 to 280
Calculation steps:
[( 280 - 307 ) ÷ 307] x 100 = -8.79%
Formula
Percentage change = [(280 - 307) / 307] x 100
Subtract the new number by the original number
280 - 307 = -27
-27 ÷ 307 = -0.08794788273615635
-0.08794788273615635 x 100 = -8.79%