-50.25% is the change from 991 to 493
Calculation steps:
[( 493 - 991 ) ÷ 991] x 100 = -50.25%
Formula
Percentage change = [(493 - 991) / 991] x 100
Subtract the new number by the original number
493 - 991 = -498
-498 ÷ 991 = -0.5025227043390514
-0.5025227043390514 x 100 = -50.25%