-49.45% is the change from 635 to 321
Calculation steps:
[( 321 - 635 ) ÷ 635] x 100 = -49.45%
Formula
Percentage change = [(321 - 635) / 635] x 100
Subtract the new number by the original number
321 - 635 = -314
-314 ÷ 635 = -0.494488188976378
-0.494488188976378 x 100 = -49.45%