-41.07% is the change from 521 to 307
Calculation steps:
[( 307 - 521 ) ÷ 521] x 100 = -41.07%
Formula
Percentage change = [(307 - 521) / 521] x 100
Subtract the new number by the original number
307 - 521 = -214
-214 ÷ 521 = -0.4107485604606526
-0.4107485604606526 x 100 = -41.07%