-6.65% is the change from 451 to 421
Calculation steps:
[( 421 - 451 ) ÷ 451] x 100 = -6.65%
Formula
Percentage change = [(421 - 451) / 451] x 100
Subtract the new number by the original number
421 - 451 = -30
-30 ÷ 451 = -0.06651884700665188
-0.06651884700665188 x 100 = -6.65%