-70.51% is the change from 851 to 251
Calculation steps:
[( 251 - 851 ) ÷ 851] x 100 = -70.51%
Formula
Percentage change = [(251 - 851) / 851] x 100
Subtract the new number by the original number
251 - 851 = -600
-600 ÷ 851 = -0.7050528789659224
-0.7050528789659224 x 100 = -70.51%