-91.86% is the change from 639 to 52
Calculation steps:
[( 52 - 639 ) ÷ 639] x 100 = -91.86%
Formula
Percentage change = [(52 - 639) / 639] x 100
Subtract the new number by the original number
52 - 639 = -587
-587 ÷ 639 = -0.918622848200313
-0.918622848200313 x 100 = -91.86%