640% is the change from 135 to 999
Calculation steps:
[( 999 - 135 ) ÷ 135] x 100 = 640%
Formula
Percentage change = [(999 - 135) / 135] x 100
Subtract the new number by the original number
999 - 135 = 864
864 ÷ 135 = 6.4
6.4 x 100 = 640%
Example