-21.75% is the change from 538 to 421
Calculation steps:
[( 421 - 538 ) ÷ 538] x 100 = -21.75%
Formula
Percentage change = [(421 - 538) / 538] x 100
Subtract the new number by the original number
421 - 538 = -117
-117 ÷ 538 = -0.2174721189591078
-0.2174721189591078 x 100 = -21.75%