-6.89% is the change from 421 to 392
Calculation steps:
[( 392 - 421 ) ÷ 421] x 100 = -6.89%
Formula
Percentage change = [(392 - 421) / 421] x 100
Subtract the new number by the original number
392 - 421 = -29
-29 ÷ 421 = -0.0688836104513064
-0.0688836104513064 x 100 = -6.89%