-3.38% is the change from 266 to 257
Calculation steps:
[( 257 - 266 ) ÷ 266] x 100 = -3.38%
Formula
Percentage change = [(257 - 266) / 266] x 100
Subtract the new number by the original number
257 - 266 = -9
-9 ÷ 266 = -0.03383458646616541
-0.03383458646616541 x 100 = -3.38%