-27.79% is the change from 421 to 304
Calculation steps:
[( 304 - 421 ) ÷ 421] x 100 = -27.79%
Formula
Percentage change = [(304 - 421) / 421] x 100
Subtract the new number by the original number
304 - 421 = -117
-117 ÷ 421 = -0.27790973871733965
-0.27790973871733965 x 100 = -27.79%