-61.5% is the change from 639 to 246
Calculation steps:
[( 246 - 639 ) ÷ 639] x 100 = -61.5%
Formula
Percentage change = [(246 - 639) / 639] x 100
Subtract the new number by the original number
246 - 639 = -393
-393 ÷ 639 = -0.6150234741784038
-0.6150234741784038 x 100 = -61.5%