-57.55% is the change from 921 to 391
Calculation steps:
[( 391 - 921 ) ÷ 921] x 100 = -57.55%
Formula
Percentage change = [(391 - 921) / 921] x 100
Subtract the new number by the original number
391 - 921 = -530
-530 ÷ 921 = -0.5754614549402823
-0.5754614549402823 x 100 = -57.55%