-18.3% is the change from 306 to 250
Calculation steps:
[( 250 - 306 ) ÷ 306] x 100 = -18.3%
Formula
Percentage change = [(250 - 306) / 306] x 100
Subtract the new number by the original number
250 - 306 = -56
-56 ÷ 306 = -0.1830065359477124
-0.1830065359477124 x 100 = -18.3%