-80.61% is the change from 521 to 101
Calculation steps:
[( 101 - 521 ) ÷ 521] x 100 = -80.61%
Formula
Percentage change = [(101 - 521) / 521] x 100
Subtract the new number by the original number
101 - 521 = -420
-420 ÷ 521 = -0.8061420345489443
-0.8061420345489443 x 100 = -80.61%