-21.48% is the change from 405 to 318
Calculation steps:
[( 318 - 405 ) ÷ 405] x 100 = -21.48%
Formula
Percentage change = [(318 - 405) / 405] x 100
Subtract the new number by the original number
318 - 405 = -87
-87 ÷ 405 = -0.21481481481481482
-0.21481481481481482 x 100 = -21.48%