-33.18% is the change from 639 to 427
Calculation steps:
[( 427 - 639 ) ÷ 639] x 100 = -33.18%
Formula
Percentage change = [(427 - 639) / 639] x 100
Subtract the new number by the original number
427 - 639 = -212
-212 ÷ 639 = -0.3317683881064163
-0.3317683881064163 x 100 = -33.18%