-5.23% is the change from 421 to 399
Calculation steps:
[( 399 - 421 ) ÷ 421] x 100 = -5.23%
Formula
Percentage change = [(399 - 421) / 421] x 100
Subtract the new number by the original number
399 - 421 = -22
-22 ÷ 421 = -0.052256532066508314
-0.052256532066508314 x 100 = -5.23%