-44.73% is the change from 921 to 509
Calculation steps:
[( 509 - 921 ) ÷ 921] x 100 = -44.73%
Formula
Percentage change = [(509 - 921) / 921] x 100
Subtract the new number by the original number
509 - 921 = -412
-412 ÷ 921 = -0.44733984799131377
-0.44733984799131377 x 100 = -44.73%