-67.6% is the change from 821 to 266
Calculation steps:
[( 266 - 821 ) ÷ 821] x 100 = -67.6%
Formula
Percentage change = [(266 - 821) / 821] x 100
Subtract the new number by the original number
266 - 821 = -555
-555 ÷ 821 = -0.6760048721071864
-0.6760048721071864 x 100 = -67.6%