-54.09% is the change from 991 to 455
Calculation steps:
[( 455 - 991 ) ÷ 991] x 100 = -54.09%
Formula
Percentage change = [(455 - 991) / 991] x 100
Subtract the new number by the original number
455 - 991 = -536
-536 ÷ 991 = -0.5408678102926338
-0.5408678102926338 x 100 = -54.09%