-91.76% is the change from 340 to 28
Calculation steps:
[( 28 - 340 ) ÷ 340] x 100 = -91.76%
Formula
Percentage change = [(28 - 340) / 340] x 100
Subtract the new number by the original number
28 - 340 = -312
-312 ÷ 340 = -0.9176470588235294
-0.9176470588235294 x 100 = -91.76%