-30.3% is the change from 439 to 306
Calculation steps:
[( 306 - 439 ) ÷ 439] x 100 = -30.3%
Formula
Percentage change = [(306 - 439) / 439] x 100
Subtract the new number by the original number
306 - 439 = -133
-133 ÷ 439 = -0.30296127562642367
-0.30296127562642367 x 100 = -30.3%