32.3% is the change from 257 to 340
Calculation steps:
[( 340 - 257 ) ÷ 257] x 100 = 32.3%
Formula
Percentage change = [(340 - 257) / 257] x 100
Subtract the new number by the original number
340 - 257 = 83
83 ÷ 257 = 0.3229571984435798
0.3229571984435798 x 100 = 32.3%