-93.11% is the change from 305 to 21
Calculation steps:
[( 21 - 305 ) ÷ 305] x 100 = -93.11%
Formula
Percentage change = [(21 - 305) / 305] x 100
Subtract the new number by the original number
21 - 305 = -284
-284 ÷ 305 = -0.9311475409836065
-0.9311475409836065 x 100 = -93.11%