56.34% is the change from 639 to 999
Calculation steps:
[( 999 - 639 ) ÷ 639] x 100 = 56.34%
Formula
Percentage change = [(999 - 639) / 639] x 100
Subtract the new number by the original number
999 - 639 = 360
360 ÷ 639 = 0.5633802816901409
0.5633802816901409 x 100 = 56.34%