-50.6% is the change from 666 to 329
Calculation steps:
[( 329 - 666 ) ÷ 666] x 100 = -50.6%
Formula
Percentage change = [(329 - 666) / 666] x 100
Subtract the new number by the original number
329 - 666 = -337
-337 ÷ 666 = -0.506006006006006
-0.506006006006006 x 100 = -50.6%