-84.82% is the change from 639 to 97
Calculation steps:
[( 97 - 639 ) ÷ 639] x 100 = -84.82%
Formula
Percentage change = [(97 - 639) / 639] x 100
Subtract the new number by the original number
97 - 639 = -542
-542 ÷ 639 = -0.8482003129890454
-0.8482003129890454 x 100 = -84.82%