219.35% is the change from 310 to 990
Calculation steps:
[( 990 - 310 ) ÷ 310] x 100 = 219.35%
Formula
Percentage change = [(990 - 310) / 310] x 100
Subtract the new number by the original number
990 - 310 = 680
680 ÷ 310 = 2.193548387096774
2.193548387096774 x 100 = 219.35%