-3.93% is the change from 815 to 783
Calculation steps:
[( 783 - 815 ) ÷ 815] x 100 = -3.93%
Formula
Percentage change = [(783 - 815) / 815] x 100
Subtract the new number by the original number
783 - 815 = -32
-32 ÷ 815 = -0.0392638036809816
-0.0392638036809816 x 100 = -3.93%