-50.05% is the change from 997 to 498
Calculation steps:
[( 498 - 997 ) ÷ 997] x 100 = -50.05%
Formula
Percentage change = [(498 - 997) / 997] x 100
Subtract the new number by the original number
498 - 997 = -499
-499 ÷ 997 = -0.5005015045135406
-0.5005015045135406 x 100 = -50.05%