-92.63% is the change from 285 to 21
Calculation steps:
[( 21 - 285 ) ÷ 285] x 100 = -92.63%
Formula
Percentage change = [(21 - 285) / 285] x 100
Subtract the new number by the original number
21 - 285 = -264
-264 ÷ 285 = -0.9263157894736842
-0.9263157894736842 x 100 = -92.63%