-69.95% is the change from 639 to 192
Calculation steps:
[( 192 - 639 ) ÷ 639] x 100 = -69.95%
Formula
Percentage change = [(192 - 639) / 639] x 100
Subtract the new number by the original number
192 - 639 = -447
-447 ÷ 639 = -0.6995305164319249
-0.6995305164319249 x 100 = -69.95%