-69.3% is the change from 834 to 256
Calculation steps:
[( 256 - 834 ) ÷ 834] x 100 = -69.3%
Formula
Percentage change = [(256 - 834) / 834] x 100
Subtract the new number by the original number
256 - 834 = -578
-578 ÷ 834 = -0.6930455635491607
-0.6930455635491607 x 100 = -69.3%