-30.22% is the change from 920 to 642
Calculation steps:
[( 642 - 920 ) ÷ 920] x 100 = -30.22%
Formula
Percentage change = [(642 - 920) / 920] x 100
Subtract the new number by the original number
642 - 920 = -278
-278 ÷ 920 = -0.30217391304347824
-0.30217391304347824 x 100 = -30.22%