-20.82% is the change from 317 to 251
Calculation steps:
[( 251 - 317 ) ÷ 317] x 100 = -20.82%
Formula
Percentage change = [(251 - 317) / 317] x 100
Subtract the new number by the original number
251 - 317 = -66
-66 ÷ 317 = -0.2082018927444795
-0.2082018927444795 x 100 = -20.82%