-50% is the change from 428 to 214
Calculation steps:
[( 214 - 428 ) ÷ 428] x 100 = -50%
Formula
Percentage change = [(214 - 428) / 428] x 100
Subtract the new number by the original number
214 - 428 = -214
-214 ÷ 428 = -0.5
-0.5 x 100 = -50%
Example