81% is the change from 321 to 581
Calculation steps:
[( 581 - 321 ) ÷ 321] x 100 = 81%
Formula
Percentage change = [(581 - 321) / 321] x 100
Subtract the new number by the original number
581 - 321 = 260
260 ÷ 321 = 0.8099688473520249
0.8099688473520249 x 100 = 81%