-33.53% is the change from 993 to 660
Calculation steps:
[( 660 - 993 ) ÷ 993] x 100 = -33.53%
Formula
Percentage change = [(660 - 993) / 993] x 100
Subtract the new number by the original number
660 - 993 = -333
-333 ÷ 993 = -0.33534743202416917
-0.33534743202416917 x 100 = -33.53%