-2.1% is the change from 429 to 420
Calculation steps:
[( 420 - 429 ) ÷ 429] x 100 = -2.1%
Formula
Percentage change = [(420 - 429) / 429] x 100
Subtract the new number by the original number
420 - 429 = -9
-9 ÷ 429 = -0.02097902097902098
-0.02097902097902098 x 100 = -2.1%