-74.49% is the change from 639 to 163
Calculation steps:
[( 163 - 639 ) ÷ 639] x 100 = -74.49%
Formula
Percentage change = [(163 - 639) / 639] x 100
Subtract the new number by the original number
163 - 639 = -476
-476 ÷ 639 = -0.7449139280125195
-0.7449139280125195 x 100 = -74.49%