-35.05% is the change from 639 to 415
Calculation steps:
[( 415 - 639 ) ÷ 639] x 100 = -35.05%
Formula
Percentage change = [(415 - 639) / 639] x 100
Subtract the new number by the original number
415 - 639 = -224
-224 ÷ 639 = -0.350547730829421
-0.350547730829421 x 100 = -35.05%