-21.93% is the change from 830 to 648
Calculation steps:
[( 648 - 830 ) ÷ 830] x 100 = -21.93%
Formula
Percentage change = [(648 - 830) / 830] x 100
Subtract the new number by the original number
648 - 830 = -182
-182 ÷ 830 = -0.21927710843373494
-0.21927710843373494 x 100 = -21.93%