-91.86% is the change from 258 to 21
Calculation steps:
[( 21 - 258 ) ÷ 258] x 100 = -91.86%
Formula
Percentage change = [(21 - 258) / 258] x 100
Subtract the new number by the original number
21 - 258 = -237
-237 ÷ 258 = -0.9186046511627907
-0.9186046511627907 x 100 = -91.86%