-90.35% is the change from 311 to 30
Calculation steps:
[( 30 - 311 ) ÷ 311] x 100 = -90.35%
Formula
Percentage change = [(30 - 311) / 311] x 100
Subtract the new number by the original number
30 - 311 = -281
-281 ÷ 311 = -0.9035369774919614
-0.9035369774919614 x 100 = -90.35%