-34.29% is the change from 977 to 642
Calculation steps:
[( 642 - 977 ) ÷ 977] x 100 = -34.29%
Formula
Percentage change = [(642 - 977) / 977] x 100
Subtract the new number by the original number
642 - 977 = -335
-335 ÷ 977 = -0.3428863868986694
-0.3428863868986694 x 100 = -34.29%