3.21% is the change from 249 to 257
Calculation steps:
[( 257 - 249 ) ÷ 249] x 100 = 3.21%
Formula
Percentage change = [(257 - 249) / 249] x 100
Subtract the new number by the original number
257 - 249 = 8
8 ÷ 249 = 0.0321285140562249
0.0321285140562249 x 100 = 3.21%