-51.6% is the change from 657 to 318
Calculation steps:
[( 318 - 657 ) ÷ 657] x 100 = -51.6%
Formula
Percentage change = [(318 - 657) / 657] x 100
Subtract the new number by the original number
318 - 657 = -339
-339 ÷ 657 = -0.5159817351598174
-0.5159817351598174 x 100 = -51.6%