-61.03% is the change from 639 to 249
Calculation steps:
[( 249 - 639 ) ÷ 639] x 100 = -61.03%
Formula
Percentage change = [(249 - 639) / 639] x 100
Subtract the new number by the original number
249 - 639 = -390
-390 ÷ 639 = -0.6103286384976526
-0.6103286384976526 x 100 = -61.03%