-61.53% is the change from 668 to 257
Calculation steps:
[( 257 - 668 ) ÷ 668] x 100 = -61.53%
Formula
Percentage change = [(257 - 668) / 668] x 100
Subtract the new number by the original number
257 - 668 = -411
-411 ÷ 668 = -0.6152694610778443
-0.6152694610778443 x 100 = -61.53%