-41.2% is the change from 830 to 488
Calculation steps:
[( 488 - 830 ) ÷ 830] x 100 = -41.2%
Formula
Percentage change = [(488 - 830) / 830] x 100
Subtract the new number by the original number
488 - 830 = -342
-342 ÷ 830 = -0.41204819277108434
-0.41204819277108434 x 100 = -41.2%