-66.99% is the change from 821 to 271
Calculation steps:
[( 271 - 821 ) ÷ 821] x 100 = -66.99%
Formula
Percentage change = [(271 - 821) / 821] x 100
Subtract the new number by the original number
271 - 821 = -550
-550 ÷ 821 = -0.6699147381242387
-0.6699147381242387 x 100 = -66.99%