27.1% is the change from 642 to 816
Calculation steps:
[( 816 - 642 ) ÷ 642] x 100 = 27.1%
Formula
Percentage change = [(816 - 642) / 642] x 100
Subtract the new number by the original number
816 - 642 = 174
174 ÷ 642 = 0.27102803738317754
0.27102803738317754 x 100 = 27.1%