-58.65% is the change from 520 to 215
Calculation steps:
[( 215 - 520 ) ÷ 520] x 100 = -58.65%
Formula
Percentage change = [(215 - 520) / 520] x 100
Subtract the new number by the original number
215 - 520 = -305
-305 ÷ 520 = -0.5865384615384616
-0.5865384615384616 x 100 = -58.65%