-48.95% is the change from 997 to 509
Calculation steps:
[( 509 - 997 ) ÷ 997] x 100 = -48.95%
Formula
Percentage change = [(509 - 997) / 997] x 100
Subtract the new number by the original number
509 - 997 = -488
-488 ÷ 997 = -0.48946840521564694
-0.48946840521564694 x 100 = -48.95%