-33.5% is the change from 997 to 663
Calculation steps:
[( 663 - 997 ) ÷ 997] x 100 = -33.5%
Formula
Percentage change = [(663 - 997) / 997] x 100
Subtract the new number by the original number
663 - 997 = -334
-334 ÷ 997 = -0.3350050150451354
-0.3350050150451354 x 100 = -33.5%