138.6% is the change from 342 to 816
Calculation steps:
[( 816 - 342 ) ÷ 342] x 100 = 138.6%
Formula
Percentage change = [(816 - 342) / 342] x 100
Subtract the new number by the original number
816 - 342 = 474
474 ÷ 342 = 1.3859649122807018
1.3859649122807018 x 100 = 138.6%