-50.46% is the change from 648 to 321
Calculation steps:
[( 321 - 648 ) ÷ 648] x 100 = -50.46%
Formula
Percentage change = [(321 - 648) / 648] x 100
Subtract the new number by the original number
321 - 648 = -327
-327 ÷ 648 = -0.5046296296296297
-0.5046296296296297 x 100 = -50.46%