-49.3% is the change from 647 to 328
Calculation steps:
[( 328 - 647 ) ÷ 647] x 100 = -49.3%
Formula
Percentage change = [(328 - 647) / 647] x 100
Subtract the new number by the original number
328 - 647 = -319
-319 ÷ 647 = -0.49304482225656876
-0.49304482225656876 x 100 = -49.3%