-40.12% is the change from 830 to 497
Calculation steps:
[( 497 - 830 ) ÷ 830] x 100 = -40.12%
Formula
Percentage change = [(497 - 830) / 830] x 100
Subtract the new number by the original number
497 - 830 = -333
-333 ÷ 830 = -0.40120481927710844
-0.40120481927710844 x 100 = -40.12%