-83.87% is the change from 620 to 100
Calculation steps:
[( 100 - 620 ) ÷ 620] x 100 = -83.87%
Formula
Percentage change = [(100 - 620) / 620] x 100
Subtract the new number by the original number
100 - 620 = -520
-520 ÷ 620 = -0.8387096774193549
-0.8387096774193549 x 100 = -83.87%