501.81% is the change from 166 to 999
Calculation steps:
[( 999 - 166 ) ÷ 166] x 100 = 501.81%
Formula
Percentage change = [(999 - 166) / 166] x 100
Subtract the new number by the original number
999 - 166 = 833
833 ÷ 166 = 5.018072289156627
5.018072289156627 x 100 = 501.81%