168.3% is the change from 306 to 821
Calculation steps:
[( 821 - 306 ) ÷ 306] x 100 = 168.3%
Formula
Percentage change = [(821 - 306) / 306] x 100
Subtract the new number by the original number
821 - 306 = 515
515 ÷ 306 = 1.6830065359477124
1.6830065359477124 x 100 = 168.3%