-1.34% is the change from 820 to 809
Calculation steps:
[( 809 - 820 ) ÷ 820] x 100 = -1.34%
Formula
Percentage change = [(809 - 820) / 820] x 100
Subtract the new number by the original number
809 - 820 = -11
-11 ÷ 820 = -0.013414634146341463
-0.013414634146341463 x 100 = -1.34%