-31.37% is the change from 306 to 210
Calculation steps:
[( 210 - 306 ) ÷ 306] x 100 = -31.37%
Formula
Percentage change = [(210 - 306) / 306] x 100
Subtract the new number by the original number
210 - 306 = -96
-96 ÷ 306 = -0.3137254901960784
-0.3137254901960784 x 100 = -31.37%