-80.09% is the change from 643 to 128
Calculation steps:
[( 128 - 643 ) ÷ 643] x 100 = -80.09%
Formula
Percentage change = [(128 - 643) / 643] x 100
Subtract the new number by the original number
128 - 643 = -515
-515 ÷ 643 = -0.8009331259720062
-0.8009331259720062 x 100 = -80.09%