-31.47% is the change from 251 to 172
Calculation steps:
[( 172 - 251 ) ÷ 251] x 100 = -31.47%
Formula
Percentage change = [(172 - 251) / 251] x 100
Subtract the new number by the original number
172 - 251 = -79
-79 ÷ 251 = -0.3147410358565737
-0.3147410358565737 x 100 = -31.47%