-69.01% is the change from 639 to 198
Calculation steps:
[( 198 - 639 ) ÷ 639] x 100 = -69.01%
Formula
Percentage change = [(198 - 639) / 639] x 100
Subtract the new number by the original number
198 - 639 = -441
-441 ÷ 639 = -0.6901408450704225
-0.6901408450704225 x 100 = -69.01%