800% is the change from 34 to 306
Calculation steps:
[( 306 - 34 ) ÷ 34] x 100 = 800%
Formula
Percentage change = [(306 - 34) / 34] x 100
Subtract the new number by the original number
306 - 34 = 272
272 ÷ 34 = 8
8 x 100 = 800%
Example