27.19% is the change from 640 to 814
Calculation steps:
[( 814 - 640 ) ÷ 640] x 100 = 27.19%
Formula
Percentage change = [(814 - 640) / 640] x 100
Subtract the new number by the original number
814 - 640 = 174
174 ÷ 640 = 0.271875
0.271875 x 100 = 27.19%