-13.44% is the change from 521 to 451
Calculation steps:
[( 451 - 521 ) ÷ 521] x 100 = -13.44%
Formula
Percentage change = [(451 - 521) / 521] x 100
Subtract the new number by the original number
451 - 521 = -70
-70 ÷ 521 = -0.1343570057581574
-0.1343570057581574 x 100 = -13.44%