-83.7% is the change from 497 to 81
Calculation steps:
[( 81 - 497 ) ÷ 497] x 100 = -83.7%
Formula
Percentage change = [(81 - 497) / 497] x 100
Subtract the new number by the original number
81 - 497 = -416
-416 ÷ 497 = -0.8370221327967807
-0.8370221327967807 x 100 = -83.7%