-98.66% is the change from 521 to 7
Calculation steps:
[( 7 - 521 ) ÷ 521] x 100 = -98.66%
Formula
Percentage change = [(7 - 521) / 521] x 100
Subtract the new number by the original number
7 - 521 = -514
-514 ÷ 521 = -0.9865642994241842
-0.9865642994241842 x 100 = -98.66%