-49.3% is the change from 645 to 327
Calculation steps:
[( 327 - 645 ) ÷ 645] x 100 = -49.3%
Formula
Percentage change = [(327 - 645) / 645] x 100
Subtract the new number by the original number
327 - 645 = -318
-318 ÷ 645 = -0.4930232558139535
-0.4930232558139535 x 100 = -49.3%