283.95% is the change from 81 to 311
Calculation steps:
[( 311 - 81 ) ÷ 81] x 100 = 283.95%
Formula
Percentage change = [(311 - 81) / 81] x 100
Subtract the new number by the original number
311 - 81 = 230
230 ÷ 81 = 2.8395061728395063
2.8395061728395063 x 100 = 283.95%