-30.24% is the change from 830 to 579
Calculation steps:
[( 579 - 830 ) ÷ 830] x 100 = -30.24%
Formula
Percentage change = [(579 - 830) / 830] x 100
Subtract the new number by the original number
579 - 830 = -251
-251 ÷ 830 = -0.3024096385542169
-0.3024096385542169 x 100 = -30.24%