-80.42% is the change from 521 to 102
Calculation steps:
[( 102 - 521 ) ÷ 521] x 100 = -80.42%
Formula
Percentage change = [(102 - 521) / 521] x 100
Subtract the new number by the original number
102 - 521 = -419
-419 ÷ 521 = -0.8042226487523992
-0.8042226487523992 x 100 = -80.42%