-63.18% is the change from 831 to 306
Calculation steps:
[( 306 - 831 ) ÷ 831] x 100 = -63.18%
Formula
Percentage change = [(306 - 831) / 831] x 100
Subtract the new number by the original number
306 - 831 = -525
-525 ÷ 831 = -0.631768953068592
-0.631768953068592 x 100 = -63.18%