-49.85% is the change from 666 to 334
Calculation steps:
[( 334 - 666 ) ÷ 666] x 100 = -49.85%
Formula
Percentage change = [(334 - 666) / 666] x 100
Subtract the new number by the original number
334 - 666 = -332
-332 ÷ 666 = -0.4984984984984985
-0.4984984984984985 x 100 = -49.85%