-8.34% is the change from 851 to 780
Calculation steps:
[( 780 - 851 ) ÷ 851] x 100 = -8.34%
Formula
Percentage change = [(780 - 851) / 851] x 100
Subtract the new number by the original number
780 - 851 = -71
-71 ÷ 851 = -0.08343125734430082
-0.08343125734430082 x 100 = -8.34%