-21.38% is the change from 407 to 320
Calculation steps:
[( 320 - 407 ) ÷ 407] x 100 = -21.38%
Formula
Percentage change = [(320 - 407) / 407] x 100
Subtract the new number by the original number
320 - 407 = -87
-87 ÷ 407 = -0.21375921375921375
-0.21375921375921375 x 100 = -21.38%