-7.69% is the change from 910 to 840
Calculation steps:
[( 840 - 910 ) ÷ 910] x 100 = -7.69%
Formula
Percentage change = [(840 - 910) / 910] x 100
Subtract the new number by the original number
840 - 910 = -70
-70 ÷ 910 = -0.07692307692307693
-0.07692307692307693 x 100 = -7.69%