-93.14% is the change from 306 to 21
Calculation steps:
[( 21 - 306 ) ÷ 306] x 100 = -93.14%
Formula
Percentage change = [(21 - 306) / 306] x 100
Subtract the new number by the original number
21 - 306 = -285
-285 ÷ 306 = -0.9313725490196079
-0.9313725490196079 x 100 = -93.14%