-83.64% is the change from 495 to 81
Calculation steps:
[( 81 - 495 ) ÷ 495] x 100 = -83.64%
Formula
Percentage change = [(81 - 495) / 495] x 100
Subtract the new number by the original number
81 - 495 = -414
-414 ÷ 495 = -0.8363636363636363
-0.8363636363636363 x 100 = -83.64%