-49.7% is the change from 666 to 335
Calculation steps:
[( 335 - 666 ) ÷ 666] x 100 = -49.7%
Formula
Percentage change = [(335 - 666) / 666] x 100
Subtract the new number by the original number
335 - 666 = -331
-331 ÷ 666 = -0.496996996996997
-0.496996996996997 x 100 = -49.7%