-3.93% is the change from 840 to 807
Calculation steps:
[( 807 - 840 ) ÷ 840] x 100 = -3.93%
Formula
Percentage change = [(807 - 840) / 840] x 100
Subtract the new number by the original number
807 - 840 = -33
-33 ÷ 840 = -0.039285714285714285
-0.039285714285714285 x 100 = -3.93%