-70.25% is the change from 521 to 155
Calculation steps:
[( 155 - 521 ) ÷ 521] x 100 = -70.25%
Formula
Percentage change = [(155 - 521) / 521] x 100
Subtract the new number by the original number
155 - 521 = -366
-366 ÷ 521 = -0.7024952015355086
-0.7024952015355086 x 100 = -70.25%