-92.22% is the change from 270 to 21
Calculation steps:
[( 21 - 270 ) ÷ 270] x 100 = -92.22%
Formula
Percentage change = [(21 - 270) / 270] x 100
Subtract the new number by the original number
21 - 270 = -249
-249 ÷ 270 = -0.9222222222222223
-0.9222222222222223 x 100 = -92.22%