15.6% is the change from 840 to 971
Calculation steps:
[( 971 - 840 ) ÷ 840] x 100 = 15.6%
Formula
Percentage change = [(971 - 840) / 840] x 100
Subtract the new number by the original number
971 - 840 = 131
131 ÷ 840 = 0.15595238095238095
0.15595238095238095 x 100 = 15.6%