-86.94% is the change from 620 to 81
Calculation steps:
[( 81 - 620 ) ÷ 620] x 100 = -86.94%
Formula
Percentage change = [(81 - 620) / 620] x 100
Subtract the new number by the original number
81 - 620 = -539
-539 ÷ 620 = -0.8693548387096774
-0.8693548387096774 x 100 = -86.94%