-6.46% is the change from 821 to 768
Calculation steps:
[( 768 - 821 ) ÷ 821] x 100 = -6.46%
Formula
Percentage change = [(768 - 821) / 821] x 100
Subtract the new number by the original number
768 - 821 = -53
-53 ÷ 821 = -0.06455542021924482
-0.06455542021924482 x 100 = -6.46%