-10.59% is the change from 321 to 287
Calculation steps:
[( 287 - 321 ) ÷ 321] x 100 = -10.59%
Formula
Percentage change = [(287 - 321) / 321] x 100
Subtract the new number by the original number
287 - 321 = -34
-34 ÷ 321 = -0.1059190031152648
-0.1059190031152648 x 100 = -10.59%