-81.4% is the change from 645 to 120
Calculation steps:
[( 120 - 645 ) ÷ 645] x 100 = -81.4%
Formula
Percentage change = [(120 - 645) / 645] x 100
Subtract the new number by the original number
120 - 645 = -525
-525 ÷ 645 = -0.813953488372093
-0.813953488372093 x 100 = -81.4%