-50.35% is the change from 991 to 492
Calculation steps:
[( 492 - 991 ) ÷ 991] x 100 = -50.35%
Formula
Percentage change = [(492 - 991) / 991] x 100
Subtract the new number by the original number
492 - 991 = -499
-499 ÷ 991 = -0.5035317860746721
-0.5035317860746721 x 100 = -50.35%