-49.81% is the change from 257 to 129
Calculation steps:
[( 129 - 257 ) ÷ 257] x 100 = -49.81%
Formula
Percentage change = [(129 - 257) / 257] x 100
Subtract the new number by the original number
129 - 257 = -128
-128 ÷ 257 = -0.4980544747081712
-0.4980544747081712 x 100 = -49.81%