-50.18% is the change from 821 to 409
Calculation steps:
[( 409 - 821 ) ÷ 821] x 100 = -50.18%
Formula
Percentage change = [(409 - 821) / 821] x 100
Subtract the new number by the original number
409 - 821 = -412
-412 ÷ 821 = -0.5018270401948843
-0.5018270401948843 x 100 = -50.18%