-8.51% is the change from 917 to 839
Calculation steps:
[( 839 - 917 ) ÷ 917] x 100 = -8.51%
Formula
Percentage change = [(839 - 917) / 917] x 100
Subtract the new number by the original number
839 - 917 = -78
-78 ÷ 917 = -0.08505997818974918
-0.08505997818974918 x 100 = -8.51%