-17.21% is the change from 773 to 640
Calculation steps:
[( 640 - 773 ) ÷ 773] x 100 = -17.21%
Formula
Percentage change = [(640 - 773) / 773] x 100
Subtract the new number by the original number
640 - 773 = -133
-133 ÷ 773 = -0.17205692108667528
-0.17205692108667528 x 100 = -17.21%