-7.94% is the change from 642 to 591
Calculation steps:
[( 591 - 642 ) ÷ 642] x 100 = -7.94%
Formula
Percentage change = [(591 - 642) / 642] x 100
Subtract the new number by the original number
591 - 642 = -51
-51 ÷ 642 = -0.0794392523364486
-0.0794392523364486 x 100 = -7.94%