42.33% is the change from 215 to 306
Calculation steps:
[( 306 - 215 ) ÷ 215] x 100 = 42.33%
Formula
Percentage change = [(306 - 215) / 215] x 100
Subtract the new number by the original number
306 - 215 = 91
91 ÷ 215 = 0.4232558139534884
0.4232558139534884 x 100 = 42.33%