-83.85% is the change from 520 to 84
Calculation steps:
[( 84 - 520 ) ÷ 520] x 100 = -83.85%
Formula
Percentage change = [(84 - 520) / 520] x 100
Subtract the new number by the original number
84 - 520 = -436
-436 ÷ 520 = -0.8384615384615385
-0.8384615384615385 x 100 = -83.85%