-6.01% is the change from 815 to 766
Calculation steps:
[( 766 - 815 ) ÷ 815] x 100 = -6.01%
Formula
Percentage change = [(766 - 815) / 815] x 100
Subtract the new number by the original number
766 - 815 = -49
-49 ÷ 815 = -0.06012269938650307
-0.06012269938650307 x 100 = -6.01%