-38.7% is the change from 540 to 331
Calculation steps:
[( 331 - 540 ) ÷ 540] x 100 = -38.7%
Formula
Percentage change = [(331 - 540) / 540] x 100
Subtract the new number by the original number
331 - 540 = -209
-209 ÷ 540 = -0.387037037037037
-0.387037037037037 x 100 = -38.7%