-0.12% is the change from 851 to 850
Calculation steps:
[( 850 - 851 ) ÷ 851] x 100 = -0.12%
Formula
Percentage change = [(850 - 851) / 851] x 100
Subtract the new number by the original number
850 - 851 = -1
-1 ÷ 851 = -0.0011750881316098707
-0.0011750881316098707 x 100 = -0.12%