21.46% is the change from 671 to 815
Calculation steps:
[( 815 - 671 ) ÷ 671] x 100 = 21.46%
Formula
Percentage change = [(815 - 671) / 671] x 100
Subtract the new number by the original number
815 - 671 = 144
144 ÷ 671 = 0.21460506706408347
0.21460506706408347 x 100 = 21.46%