285.19% is the change from 81 to 312
Calculation steps:
[( 312 - 81 ) ÷ 81] x 100 = 285.19%
Formula
Percentage change = [(312 - 81) / 81] x 100
Subtract the new number by the original number
312 - 81 = 231
231 ÷ 81 = 2.8518518518518516
2.8518518518518516 x 100 = 285.19%