-30.19% is the change from 308 to 215
Calculation steps:
[( 215 - 308 ) ÷ 308] x 100 = -30.19%
Formula
Percentage change = [(215 - 308) / 308] x 100
Subtract the new number by the original number
215 - 308 = -93
-93 ÷ 308 = -0.30194805194805197
-0.30194805194805197 x 100 = -30.19%