-50.15% is the change from 660 to 329
Calculation steps:
[( 329 - 660 ) ÷ 660] x 100 = -50.15%
Formula
Percentage change = [(329 - 660) / 660] x 100
Subtract the new number by the original number
329 - 660 = -331
-331 ÷ 660 = -0.5015151515151515
-0.5015151515151515 x 100 = -50.15%