-82.9% is the change from 497 to 85
Calculation steps:
[( 85 - 497 ) ÷ 497] x 100 = -82.9%
Formula
Percentage change = [(85 - 497) / 497] x 100
Subtract the new number by the original number
85 - 497 = -412
-412 ÷ 497 = -0.8289738430583501
-0.8289738430583501 x 100 = -82.9%