-17.9% is the change from 838 to 688
Calculation steps:
[( 688 - 838 ) ÷ 838] x 100 = -17.9%
Formula
Percentage change = [(688 - 838) / 838] x 100
Subtract the new number by the original number
688 - 838 = -150
-150 ÷ 838 = -0.17899761336515513
-0.17899761336515513 x 100 = -17.9%