-30.07% is the change from 306 to 214
Calculation steps:
[( 214 - 306 ) ÷ 306] x 100 = -30.07%
Formula
Percentage change = [(214 - 306) / 306] x 100
Subtract the new number by the original number
214 - 306 = -92
-92 ÷ 306 = -0.3006535947712418
-0.3006535947712418 x 100 = -30.07%