-47.43% is the change from 991 to 521
Calculation steps:
[( 521 - 991 ) ÷ 991] x 100 = -47.43%
Formula
Percentage change = [(521 - 991) / 991] x 100
Subtract the new number by the original number
521 - 991 = -470
-470 ÷ 991 = -0.47426841574167505
-0.47426841574167505 x 100 = -47.43%