-21.21% is the change from 495 to 390
Calculation steps:
[( 390 - 495 ) ÷ 495] x 100 = -21.21%
Formula
Percentage change = [(390 - 495) / 495] x 100
Subtract the new number by the original number
390 - 495 = -105
-105 ÷ 495 = -0.21212121212121213
-0.21212121212121213 x 100 = -21.21%