-54.05% is the change from 666 to 306
Calculation steps:
[( 306 - 666 ) ÷ 666] x 100 = -54.05%
Formula
Percentage change = [(306 - 666) / 666] x 100
Subtract the new number by the original number
306 - 666 = -360
-360 ÷ 666 = -0.5405405405405406
-0.5405405405405406 x 100 = -54.05%