-0.49% is the change from 815 to 811
Calculation steps:
[( 811 - 815 ) ÷ 815] x 100 = -0.49%
Formula
Percentage change = [(811 - 815) / 815] x 100
Subtract the new number by the original number
811 - 815 = -4
-4 ÷ 815 = -0.0049079754601227
-0.0049079754601227 x 100 = -0.49%