-66.95% is the change from 820 to 271
Calculation steps:
[( 271 - 820 ) ÷ 820] x 100 = -66.95%
Formula
Percentage change = [(271 - 820) / 820] x 100
Subtract the new number by the original number
271 - 820 = -549
-549 ÷ 820 = -0.6695121951219513
-0.6695121951219513 x 100 = -66.95%