-50.08% is the change from 663 to 331
Calculation steps:
[( 331 - 663 ) ÷ 663] x 100 = -50.08%
Formula
Percentage change = [(331 - 663) / 663] x 100
Subtract the new number by the original number
331 - 663 = -332
-332 ÷ 663 = -0.5007541478129713
-0.5007541478129713 x 100 = -50.08%