-6.34% is the change from 820 to 768
Calculation steps:
[( 768 - 820 ) ÷ 820] x 100 = -6.34%
Formula
Percentage change = [(768 - 820) / 820] x 100
Subtract the new number by the original number
768 - 820 = -52
-52 ÷ 820 = -0.06341463414634146
-0.06341463414634146 x 100 = -6.34%