-3.11% is the change from 257 to 249
Calculation steps:
[( 249 - 257 ) ÷ 257] x 100 = -3.11%
Formula
Percentage change = [(249 - 257) / 257] x 100
Subtract the new number by the original number
249 - 257 = -8
-8 ÷ 257 = -0.0311284046692607
-0.0311284046692607 x 100 = -3.11%