-49.04% is the change from 830 to 423
Calculation steps:
[( 423 - 830 ) ÷ 830] x 100 = -49.04%
Formula
Percentage change = [(423 - 830) / 830] x 100
Subtract the new number by the original number
423 - 830 = -407
-407 ÷ 830 = -0.4903614457831325
-0.4903614457831325 x 100 = -49.04%