-34.94% is the change from 830 to 540
Calculation steps:
[( 540 - 830 ) ÷ 830] x 100 = -34.94%
Formula
Percentage change = [(540 - 830) / 830] x 100
Subtract the new number by the original number
540 - 830 = -290
-290 ÷ 830 = -0.3493975903614458
-0.3493975903614458 x 100 = -34.94%