30.75% is the change from 491 to 642
Calculation steps:
[( 642 - 491 ) ÷ 491] x 100 = 30.75%
Formula
Percentage change = [(642 - 491) / 491] x 100
Subtract the new number by the original number
642 - 491 = 151
151 ÷ 491 = 0.3075356415478615
0.3075356415478615 x 100 = 30.75%