-35.6% is the change from 809 to 521
Calculation steps:
[( 521 - 809 ) ÷ 809] x 100 = -35.6%
Formula
Percentage change = [(521 - 809) / 809] x 100
Subtract the new number by the original number
521 - 809 = -288
-288 ÷ 809 = -0.35599505562422745
-0.35599505562422745 x 100 = -35.6%