200% is the change from 310 to 930
Calculation steps:
[( 930 - 310 ) ÷ 310] x 100 = 200%
Formula
Percentage change = [(930 - 310) / 310] x 100
Subtract the new number by the original number
930 - 310 = 620
620 ÷ 310 = 2
2 x 100 = 200%
Example