-54.49% is the change from 991 to 451
Calculation steps:
[( 451 - 991 ) ÷ 991] x 100 = -54.49%
Formula
Percentage change = [(451 - 991) / 991] x 100
Subtract the new number by the original number
451 - 991 = -540
-540 ÷ 991 = -0.544904137235116
-0.544904137235116 x 100 = -54.49%