-55.4% is the change from 639 to 285
Calculation steps:
[( 285 - 639 ) ÷ 639] x 100 = -55.4%
Formula
Percentage change = [(285 - 639) / 639] x 100
Subtract the new number by the original number
285 - 639 = -354
-354 ÷ 639 = -0.5539906103286385
-0.5539906103286385 x 100 = -55.4%