-21.01% is the change from 495 to 391
Calculation steps:
[( 391 - 495 ) ÷ 495] x 100 = -21.01%
Formula
Percentage change = [(391 - 495) / 495] x 100
Subtract the new number by the original number
391 - 495 = -104
-104 ÷ 495 = -0.2101010101010101
-0.2101010101010101 x 100 = -21.01%