-15.38% is the change from 910 to 770
Calculation steps:
[( 770 - 910 ) ÷ 910] x 100 = -15.38%
Formula
Percentage change = [(770 - 910) / 910] x 100
Subtract the new number by the original number
770 - 910 = -140
-140 ÷ 910 = -0.15384615384615385
-0.15384615384615385 x 100 = -15.38%