-81.38% is the change from 521 to 97
Calculation steps:
[( 97 - 521 ) ÷ 521] x 100 = -81.38%
Formula
Percentage change = [(97 - 521) / 521] x 100
Subtract the new number by the original number
97 - 521 = -424
-424 ÷ 521 = -0.8138195777351248
-0.8138195777351248 x 100 = -81.38%