26.55% is the change from 644 to 815
Calculation steps:
[( 815 - 644 ) ÷ 644] x 100 = 26.55%
Formula
Percentage change = [(815 - 644) / 644] x 100
Subtract the new number by the original number
815 - 644 = 171
171 ÷ 644 = 0.265527950310559
0.265527950310559 x 100 = 26.55%