-38.53% is the change from 828 to 509
Calculation steps:
[( 509 - 828 ) ÷ 828] x 100 = -38.53%
Formula
Percentage change = [(509 - 828) / 828] x 100
Subtract the new number by the original number
509 - 828 = -319
-319 ÷ 828 = -0.3852657004830918
-0.3852657004830918 x 100 = -38.53%