-8.6% is the change from 919 to 840
Calculation steps:
[( 840 - 919 ) ÷ 919] x 100 = -8.6%
Formula
Percentage change = [(840 - 919) / 919] x 100
Subtract the new number by the original number
840 - 919 = -79
-79 ÷ 919 = -0.08596300326441784
-0.08596300326441784 x 100 = -8.6%