-94% is the change from 850 to 51
Calculation steps:
[( 51 - 850 ) ÷ 850] x 100 = -94%
Formula
Percentage change = [(51 - 850) / 850] x 100
Subtract the new number by the original number
51 - 850 = -799
-799 ÷ 850 = -0.94
-0.94 x 100 = -94%
Example