228.93% is the change from 280 to 921
Calculation steps:
[( 921 - 280 ) ÷ 280] x 100 = 228.93%
Formula
Percentage change = [(921 - 280) / 280] x 100
Subtract the new number by the original number
921 - 280 = 641
641 ÷ 280 = 2.289285714285714
2.289285714285714 x 100 = 228.93%