-16.3% is the change from 503 to 421
Calculation steps:
[( 421 - 503 ) ÷ 503] x 100 = -16.3%
Formula
Percentage change = [(421 - 503) / 503] x 100
Subtract the new number by the original number
421 - 503 = -82
-82 ÷ 503 = -0.16302186878727634
-0.16302186878727634 x 100 = -16.3%