-30.07% is the change from 918 to 642
Calculation steps:
[( 642 - 918 ) ÷ 918] x 100 = -30.07%
Formula
Percentage change = [(642 - 918) / 918] x 100
Subtract the new number by the original number
642 - 918 = -276
-276 ÷ 918 = -0.3006535947712418
-0.3006535947712418 x 100 = -30.07%