51.18% is the change from 170 to 257
Calculation steps:
[( 257 - 170 ) ÷ 170] x 100 = 51.18%
Formula
Percentage change = [(257 - 170) / 170] x 100
Subtract the new number by the original number
257 - 170 = 87
87 ÷ 170 = 0.5117647058823529
0.5117647058823529 x 100 = 51.18%