-70.74% is the change from 639 to 187
Calculation steps:
[( 187 - 639 ) ÷ 639] x 100 = -70.74%
Formula
Percentage change = [(187 - 639) / 639] x 100
Subtract the new number by the original number
187 - 639 = -452
-452 ÷ 639 = -0.7073552425665102
-0.7073552425665102 x 100 = -70.74%