-70.58% is the change from 639 to 188
Calculation steps:
[( 188 - 639 ) ÷ 639] x 100 = -70.58%
Formula
Percentage change = [(188 - 639) / 639] x 100
Subtract the new number by the original number
188 - 639 = -451
-451 ÷ 639 = -0.7057902973395931
-0.7057902973395931 x 100 = -70.58%