-7.84% is the change from 421 to 388
Calculation steps:
[( 388 - 421 ) ÷ 421] x 100 = -7.84%
Formula
Percentage change = [(388 - 421) / 421] x 100
Subtract the new number by the original number
388 - 421 = -33
-33 ÷ 421 = -0.07838479809976247
-0.07838479809976247 x 100 = -7.84%