-91.07% is the change from 336 to 30
Calculation steps:
[( 30 - 336 ) ÷ 336] x 100 = -91.07%
Formula
Percentage change = [(30 - 336) / 336] x 100
Subtract the new number by the original number
30 - 336 = -306
-306 ÷ 336 = -0.9107142857142857
-0.9107142857142857 x 100 = -91.07%