-36.39% is the change from 830 to 528
Calculation steps:
[( 528 - 830 ) ÷ 830] x 100 = -36.39%
Formula
Percentage change = [(528 - 830) / 830] x 100
Subtract the new number by the original number
528 - 830 = -302
-302 ÷ 830 = -0.363855421686747
-0.363855421686747 x 100 = -36.39%