-30.48% is the change from 830 to 577
Calculation steps:
[( 577 - 830 ) ÷ 830] x 100 = -30.48%
Formula
Percentage change = [(577 - 830) / 830] x 100
Subtract the new number by the original number
577 - 830 = -253
-253 ÷ 830 = -0.30481927710843376
-0.30481927710843376 x 100 = -30.48%