-30.72% is the change from 306 to 212
Calculation steps:
[( 212 - 306 ) ÷ 306] x 100 = -30.72%
Formula
Percentage change = [(212 - 306) / 306] x 100
Subtract the new number by the original number
212 - 306 = -94
-94 ÷ 306 = -0.30718954248366015
-0.30718954248366015 x 100 = -30.72%