25.94% is the change from 640 to 806
Calculation steps:
[( 806 - 640 ) ÷ 640] x 100 = 25.94%
Formula
Percentage change = [(806 - 640) / 640] x 100
Subtract the new number by the original number
806 - 640 = 166
166 ÷ 640 = 0.259375
0.259375 x 100 = 25.94%