-23.5% is the change from 834 to 638
Calculation steps:
[( 638 - 834 ) ÷ 834] x 100 = -23.5%
Formula
Percentage change = [(638 - 834) / 834] x 100
Subtract the new number by the original number
638 - 834 = -196
-196 ÷ 834 = -0.23501199040767387
-0.23501199040767387 x 100 = -23.5%