-25.07% is the change from 343 to 257
Calculation steps:
[( 257 - 343 ) ÷ 343] x 100 = -25.07%
Formula
Percentage change = [(257 - 343) / 343] x 100
Subtract the new number by the original number
257 - 343 = -86
-86 ÷ 343 = -0.25072886297376096
-0.25072886297376096 x 100 = -25.07%