-10.9% is the change from 321 to 286
Calculation steps:
[( 286 - 321 ) ÷ 321] x 100 = -10.9%
Formula
Percentage change = [(286 - 321) / 321] x 100
Subtract the new number by the original number
286 - 321 = -35
-35 ÷ 321 = -0.10903426791277258
-0.10903426791277258 x 100 = -10.9%