-5.52% is the change from 815 to 770
Calculation steps:
[( 770 - 815 ) ÷ 815] x 100 = -5.52%
Formula
Percentage change = [(770 - 815) / 815] x 100
Subtract the new number by the original number
770 - 815 = -45
-45 ÷ 815 = -0.05521472392638037
-0.05521472392638037 x 100 = -5.52%